Effect of Qihong Capsule on Heart Hemodynamics and Myocardial Consumption of Oxygen in Heart Failure Model Beagle / 中国实验方剂学杂志

Objective:To investigate the therapeutic effect of Qihong capsule on pentobarbital sodium induced heart failure in beagle dogs. Method:Thirty healthy adult beagle dogs were randomly divided into 6 groups, 6 in each group. They were normal group, model group, digoxin tablet group (40 μg·kg-1), Qihong capsule high, medium and low dose groups (2.6，1.3，0.65 g·kg-1). The heart failure model of beagle dogs was established by intravenous infusion of 2% pentobarbital sodium. The success standard of the model was that the maximum rate of rise of left ventricular pressure was reduced by 70%.The corresponding drugs were given through duodenum. The Ⅱ lead electrocardiogram, coronary blood flow, cardiac output, left ventricular pressure and maximum rate of left ventricular pressure rise were measured by multi-channel physiological recorder. The arterial oxygen content and coronary sinus oxygen content were measured by Roche blood oxygen analyzer at different time points, and the myocardial oxygen utilization rate was calculated. Result:After intravenous infusion of 2% pentobarbital sodium for about 15 minutes, beagle dogs began to show obvious symptoms of heart failure. The main manifestations were the increase of PR interval of Ⅱ lead electrocardiogram, the decrease of coronary blood flow, left ventricular pressure, cardiac output, cardiac output, venous oxygen content, and the increase of myocardial oxygen utilization rate (P<0.01) compared with the model group, Qihong capsule significantly increased coronary blood flow at 60-120 min after treatment (P<0.05). The cardiac output of 2.6 g·kg-1 Qihong capsule increased significantly at 45-60 min after treatment, with the maximum increase of about 16%, which was significantly different from that of model group (P<0.05). At the same time, it can increase the oxygen content of coronary sinus blood, which indicates that the myocardial oxygen supply is increased and the oxygen utilization rate is decreased. Qihong capsule 1.3 g·kg-1 group significantly increased the maximum rate of left ventricular pressure rise (P<0.05), the maximum increase rate was about 42%. Conclusion:Qihong capsule can increase coronary blood flow and venous blood oxygen content at the same time, make myocardial nutrient supply sufficient, reduce oxygen utilization rate, on this basis, Qihong capsule can further increase cardiac output and improve cardiac function, so as to play a protective role in heart failure.

Study on the association of hypersensitivity troponin T level with coronary flow in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention / 中国生化药物杂志

Objective To study the the association of Hs-cTNT level with coronary flow in patients with ST-segment elevation myocardial infarction(STEMI) undergoing percutaneous coronary intervention(PCI).Methods130 cases with STEMI in hospital from January 2014 to December 2014 were divided into the positive group and the negative group according the level of Hs-cTNT.Multivariate analysis were used to examine the association of Hs-cTNT with coronary flow in patients with ST-Segment elevation myocardial infarction undergoing primary PCI.ResultsThe incidence of no reflow in the positive group was significantly higher than that in the negative group (P<0.05) The left ventricular ejection fraction in the positive group was significantly lower than that in the negative group (P<0.05).Multivariate analysis showed that Hs-cTNT was independently associated with coronary flow no-reflow in patients with acute STEMI post-PCI and TIMI flow fractionation events(P<0.05).ConclusionHypersensitivity troponin T is an effective marker for predicting coronary artery flow damage in patients with STEMI after PCI and evaluating risk stratification in patients with STEMI.

Effects of Titrofiban with Different Medication Timing on Blood Flow and Complications in Patients with Acute Myocardial Infarction after Percutaneous Coronary Intervention / 中国药房

OBJECTIVE:To explore the effects of tirofiban with different medication timing on blood flow and complications in patients with acute myocardial infarction after percutaneous coronary intervention(PCI). METHODS:214 cases of acute ST-seg-ment elevation myocardial infarction were divided into late stage group(n=98)and early stage group(n=116)based on the order of admission. Te latter was given intravenous injection of tirofiban after PCI;the former was given intravenous injection of tirofi-ban before entered emergency room [1-2 h before PCI]. The injection-balloon dilation time was compared between 2 groups. The coronary TIMI flow situation,cardiac function and microcirculatory perfusion index before and after operation,and complications during hospitalization were also compared. RESULTS:Intravenous injection of tirofiban to balloon dilation time were 3-40 min in early stage group,and 30-65 min in late stage group,with statistical significance (t=8.94,P=0.00);during angiography,the number of patients with IRA prorsal blood flow rate to reach 2 and 3 grade was 16 cases(13.8% and 20 cases(17.2%)in early stage group,which were higher than in late stage group [7 cases (7.1%),9 cases (9.2%)],with statistical significance (P0.05). The amount of 4 and 8 h creatine kinase MB,and postoperative 24 h LVEF of 2 groups were similar after operation,without statistical significance (P>0.05);ST segment of early stage group drop value was (1.93 ± 0.57) mm,which was significantly higher than that of late stage group(1.07±0.29)mm,with statistical significance(P<0.05);the incidence of cardiac adverse events and bleeding compli-cation were 3.45%and 7.76%in early stage group,and 4.08%and 5.10%in late-stage group,without statistical significance(P<0.05). CONCLUSIONS:Different medication timing has no significant effect on the safety of tirofiban,but clinical outcomes and angiographic results are consistent. However,early treatment can improve IRA prorsal blood flow rate before PCI,which is the good medication timing of tirofiban.

Importancia de la cuantificación del flujo coronario mediante PET, en pacientes con enfermedad trivascular / The importance of myocardial blood flow quantification with positron emission tomography (PET) in patients with three-vessel disease

El estudio de perfusión miocárdica mediante tomografía computada por emisión de fotón único es una técnica ampliamente aceptada con alta sensibilidad y especificidad. Una de las limitaciones de esta técnica es el diagnóstico de enfermedad trivascular, debido al fenómeno de hipoperfusión global balanceada. La adición de los estudios con tomografía por emisión de positrones, permite no sólo el análisis de la perfusión y de la función ventricular, sino también la cuantificación del flujo coronario en mL/g/min de tejido miocárdico y por lo tanto, la determinación de la reserva de flujo coronario, la cual se ha relacionado claramente con la presencia de estenosis coronaria. El propósito de este trabajo es demostrar a través de un caso clínico y revisión de la literatura médica, la importancia del estudio del flujo coronario de forma no invasiva en los pacientes con enfermedad trivascular.

The study of patients with coronary artery disease by means of gated SPECT has been well established. One of the major limitations of this technique is the detection of myocardial perfusion defects in the presence of multivessel or three-vessel coronary artery disease due to balanced ischemia. Quantification of myocardial blood flow by positron emission tomography allows not only to study cardiac perfusion and function but also to determine the coronary flow reserve which has a better correlation with significant stenosis in patients with trivascular disease. The aim of this study was to demonstrate through a case report and literature review the importance of performing quantification of coronary blood flow in this group of patients.

Treinamento físico de natação promove remodelamento cardíaco e melhora a perfusão sanguínea no músculo cardíaco de SHR via mecanismo dependente de adenosina / Swimming physical training promotes cardiac remodeling and improves

INTRODUÇÃO: Exercícios físicos são utilizados como terapia não farmacológica para o tratamento da hipertensão arterial, e o treinamento físico (TF) por natação é reconhecido por produzir remodelamento cardíaco em animais experimentais. Entretanto, a ação vasodilatadora da adenosina (ado) resultante do exercício físico como prevenção e tratamento da hipertensão é pouco explorada. OBJETIVO: Avaliar o remodelamento cardíaco e o papel da adenosina na distribuição do fluxo sanguíneo para o miocárdio após treinamento físico em SHR. Método: 28 SHR machos babies e adultos foram submetidos ao TF aeróbio de natação, durante 10 semanas (5x/sem -1h/dia). Foram utilizados protocolos de microesferas coloridas para avaliar fluxo sanguíneo, técnicas de morfologia para avaliar hipertrofia cardíaca e análises bioquímicas para verificar atividade de enzimas envolvidas na formação de adenosina. RESULTADOS: TF por natação atenuou a evolução da HA em SHR babies (S: 145 ± 2; T: 140 ± 2mmHg), promoveu bradicardia de repouso em SHR adultos (S: 340 ± 4; T: 321 ± 6bpm) e desenvolveu HC nos dois grupos (TB: 12 por cento; TA: 10 por cento). Na condição basal, o TF aumentou o FS coronário em SHR babies (S: 4.745 ± 2.145; T: 6.970 ± 2.374mi/coração) e maior resposta vasodilatadora à infusão de adenosina foi observada (S: 18.946 ± 6.685; T: 25.045 ± 7.031mi/coração). Neste grupo, o TF promoveu maior atividade da enzima 5'-nucleotidase, levando à maior formação de adenosina (S: 0,45 ± 0,09; T: 1,01 ± 0,05). CONCLUSÃO: O TF de natação, além de desenvolver HC e apresentar maior hidrólise de AMP, promoveu aumento no FS coronário, sendo mostrado que desempenha um importante papel na regulação da hipertensão.

Exercise training (ET) has been used as non-pharmacological therapy for hypertension treatment and swimming physical training is recognized for yielding cardiac remodeling in experiments. However, little is known on the effects of adenosine (Ado) resulting from ET as hypertension prevention and treatment. OBJECTIVE: To evaluate cardiac remodeling and the role of adenosine in cardiac blood flow distribution (BF) to the myocardium after aerobic ET on SHR. METHODS: 28 male SHR, babies and adults, were submitted to swimming training protocol during 10 weeks (5 times a week - 1 h a day). Colored micro spheres protocols were used to evaluate blood flow, morphological techniques were used to evaluate cardiac hypertrophy and biochemical analysis were performed to verify enzyme activity in the adenosine formation. RESULTS: ET attenuated the evolution of hypertension in the SHR babies group (S: 145 2; T: 140 2mmHg), HR was lower in adult SHR (S: 340 4; T: 321 6bpm) and CH increased in both groups (TB: 12 percent; TA: 10 percent). At basal condition, BF was increased in trained babies (S: 4.745 ± 2.145; T: 6.970 ± 2.374mi/heart) and higher vasodilatation response was observed due to adenosine infusion (S: 18.946 ± 6.685; T: 25.045 ± 7.031mi/heart). In this group, the ET promoted a higher 5'-nucleotidase enzyme activity leading to a higher adenosine formation (S: 0.45 ± 0.09; T: 1.01 ± 0.05). CONCLUSION: The swimming training developed CH as well as increased adenosine formation, leading to higher coronary blood flow, and its important role in hypertension regulation was demonstrated.

Non-invasive analysis coronary artery flow velocity of slow coronary flow phenomenon / 中华超声影像学杂志

Objective To non-invasive assess coronary blood flow velocity changes of patients with slow coronary flow phenomenon (SCFP) by coronary blood flow imaging (CFI).MethodsTwenty-one patients who had no significant coronary artery stenosis but had thrombolysis in myocardial infarction (TIMI) slow-flow phenomenon were the experimental group,nine patients who has no significant coronary stenosis and TIMI flow normal were the control group.Using corrected TIMI frame count(CTFC) assess velocity of coronary artery.The left ventricular end diastolic diameter,end systolic diameter,ejection fraction,E peak velocity,A peak velocity,E/A ratio were measured by conventional echocardiography.The distal anterior descending coronary artery diastolic peak flow velocity(Vmax),mean velocity(Vmean) and blood flow velocity time integral(VTI) were measured by CFI.Results The corrected TIMI frame count (CTFC) of left anterior descending artery blood flow in slow blood group was (45.37 ± 8.62)frame,that in control group was (15.94± 4.66)frame,the difference was statistically significant (t = -9.596,P =0.000).The conventional echocardiographic measurements of two groups were not significantly different.The left anterior descending artery Vmax was (22.86 ± 3.04)cm/s,Vmean was (17.62 ± 2.89)cm/s,VTIwas (8.49± 2.01)cm in the slow blood flow group,the left anterior descending artery Vmax was (31.78 ± 9.28) cm/s,Vmean was (23.67 ± 7.60) cm/s,VTI was (10.91 ± 4.47) cm in the control group.The difference was statistically significant.The left anterior descending artery CTFC with Vmax and Vmean was negative correlation in the control group and the slow blood flow group.The left anterior descending artery CTFC was negatively correlated with VTI in the control group,there was no correlation between left anterior descending artery CTFC and VTI in the slow blood flow group.Conclusions Coronary artery flow velocity in the left anterior descending artery was declined.CFI can reflect changes in coronary TIMI flow,but in the diagnosis of coronary slow flow phenomenon CFI has limitations.

Effects of adenosine on left coronary blood flow and flow reserve in mini-swine: a comparative study between different adenosine doses / 介入放射学杂志

Objective To compare the effects of different doses of adenosine(AD)on the left coronary blood flow(CBF)and left coronary flow reserve(CFR)in mini-swine.Methods By using Doppler flow wire and intracoronary ultrasound imaging catheter at the middle segment of LAD,coronary average peak flow velocity(APV)and lumen area were measured in 10 healthy mini-swines.CBF was calculated from the equation of 0.6 APV times 0.5 lumen area.Intracoronary bolus injection of different dose AD(12μg,18μg,24 μg and 36μg,separately)was used to induce maximal coronary hyperemic reaction.CFR was defined as the ratio of hyperemic CBF to resting CBF.Results Intracoronary bolus injection of 18μg AD level induced a maximal coronary vasodilation.Significant difference in the hyperemic CBF existed between 12 μg AD dose and 24μg or 36μg AD dose(P＜0.05).No significant difference in heart rate,blood pressure,rCBF and CFR was found among three different AD dose groups(18μg,24μg,and 36μg).Conclusion CBF and CFR in mini-swine can be effectively assessed by bolus injection of AD with the dose of(18～24)μg.

Endothelial and non-endothelial coronary blood flow reserve and left ventricular dysfunction in systemic hypertension

OBJECTIVES: We evaluated the impairment of endothelium-dependent and endothelium-independent coronary blood flow reserve after administration of intracoronary acetylcholine and adenosine, and its association with hypertensive cardiac disease. INTRODUCTION: Coronary blood flow reserve reduction has been proposed as a mechanism for the progression of compensated left ventricular hypertrophy to ventricular dysfunction. METHODS: Eighteen hypertensive patients with normal epicardial coronary arteries on angiography were divided into two groups according to left ventricular fractional shortening (FS). Group 1 (FS >0.25): n=8, FS=0.29 ± 0.03; Group 2 (FS <0.25): n=10, FS= 0.17 ± 0.03. RESULTS: Baseline coronary blood flow was similar in both groups (Group 1: 80.15 ± 26.41 mL/min, Group 2: 100.09 ± 21.51 mL/min, p=NS). In response to adenosine, coronary blood flow increased to 265.1 ± 100.2 mL/min in Group 1 and to 300.8 ± 113.6 mL/min (p <0.05) in Group 2. Endothelium-independent coronary blood flow reserve was similar in both groups (Group 1: 3.31 ± 0.68 and Group 2: 2.97 ± 0.80, p=NS). In response to acetylcholine, coronary blood flow increased to 156.08 ± 36.79 mL/min in Group 1 and to 177.8 ± 83.6 mL/min in Group 2 (p <0.05). Endothelium-dependent coronary blood flow reserve was similar in the two groups (Group 1: 2.08 ± 0.74 and group Group 2: 1.76 ± 0.61, p=NS). Peak acetylcholine/peak adenosine coronary blood flow response (Group 1: 0.65 ± 0.27 and Group 2: 0.60 ± 0.17) and minimal coronary vascular resistance (Group 1: 0.48 ± 0.21 mmHg/mL/min and Group 2: 0.34 ± 0.12 mmHg/mL/min) were similar in both groups (p= NS). Casual diastolic blood pressure and end-systolic left ventricular stress were independently associated with FS. CONCLUSIONS: In our hypertensive patients, endothelium-dependent and endothelium-independent coronary blood flow reserve vasodilator administrations had similar effects in patients with either normal or decreased ...

The Effect of Thoracic Epidural Lidocaine on Blood Flow of Grafted Coronary Vessels in Coranary Artery Bypass Graft Surgery / 대한마취과학회지

BACKGROUND: Thoracic epidural anesthesia (TEA) is increasingly used to reduce stress response, pain and pulmonary complication of patients under coronary artery bypass graft (CABG). However, effects of TEA on blood flow of grafted coronary artery are scarcely noticed. Imbalance between blood flow of grafted coronary artery and myocardial oxygen demand can bring about perioperative myocardial ischemia. Thus we evaluated the effect of TEA on blood flow of coronary grafts. METHODS: Twenty seven patients with triple-vessel coronary artery disease under CABG were recruited. Left internal mammary artery, radial artery, and great saphenous vein were anastomosed to left anterior descending artery, obtuse marginalis, and posterior descending artery, respectively. Before surgery, an epidural catheter was inserted. Total intravenous anesthesia was undertaken using fentanyl, midazolam and vecuronium. After grafts anastomosis, blood flow of grafted coronary artery was measured using transit-time flowmeter (TTFM) before weaning from CPB. And then, mixture of 2% lidocaine 10 ml, fentanyl 50microgram and bicarbonate 1 mEq was injected via epidural catheter. Under the constant pump flow, the blood flow of grafted coronary artery before, 10 and 20 minutes after drug administration were measured using TTFM. RESULTS: The blood flow of coronary artery grafts was similar in three time interval, irrespective of grafted artery. There are no significant differences in changes in coronary blood flow associated with epidural lidocaine injection among 3 types of grafted artery. CONCLUSIONS: The present study shows that there are no significant effects of TEA on blood flow of newly grafted coronary artery after CABG.

Effects of ShaJi on oxygen metabolism in myocardium of anesthetized thoraco-opened dogs / 吉林大学学报(医学版)

Objective To study the effects of ShaJi on the indexes of oxygen metabolism such as coronary blood flow in myocardium of anesthetized thoraco-opened dogs. Methods Dogs were randomly divided into control group,4 and 16 mg?kg-1 ShaJi groups,and positive control group(n=6).The anesthetized thoraco-opened dog models were set up.The administration of intravenous injection was used by femoral vein.The blood pressure,heart rate and coronary blood flow(CBF) were measured.Coronary resistance,myocardial oxygen uptake rate,myocardial oxygen consumption index and myocardial oxygen consumption were calculated.Results Compared with control group,the CBF was increased (P0.05).Conclusion ShaJi can significantly ameliorate oxygen metabolism in myocardium of anesthetized thoraco-opened dogs.

Fisiología coronaria y su utilidad para el cardiólogo intervencionista: Medición invasiva de la presión y flujo coronarios / Coronary physiology and its usefulness for the interventionist cardiologist: Invasive measurement of coronary flow-pressure

Una de las más importantes limitaciones de la angiografía coronaria es su incapacidad para determinar el impacto fisiológico de las estenosis coronarias moderadas. La medición de la presión y del flujo sanguíneo coronario nos brinda información valiosa que complementa la evaluación anatómica y facilitan la toma de decisiones en el laboratorio de cateterismo cardíaco. En esta revisión se discuten los conceptos fundamentales de la fisiología coronaria, así como la metodología y aplicación clínica de las técnicas de medición de presión y flujo coronarios.

One of the most important limitations of coronary angiography is the inability to characterize the physiological significance of an intermediate coronary stenosis. Measuring coronary blood flow and pressure provides unique information that complements anatomic evaluation and facilitates decision-making in the cardiac catheterization unit. This review discusses the fundamental concepts of coronary physiology, methodology, and clinical applications of coronary and flow measurements.

Valoración del flujo coronario mediante PET en la población mexicana sin enfermedad arterial coronaria / Evaluation of coronary flow by means of PET in the Mexican population without coronary artery disease

La enfermedad arterial coronaria (EAC) representa la primera causa de morbi mortalidad en nuestro medio. La tomografía por emisión de positrones (PET) es una técnica novedosa en nuestro país mediante la cual es posible valorar la perfusión miocárdica a través de radiotrazadores, lo que permite detectar defectos de perfusión utilizando los mismos criterios que en cardiología nuclear. A su vez, a través del estudio del flujo coronario (FC) es posible detectar la EAC en sus etapas más tempranas. El FC ha sido determinado en otras poblaciones a nivel mundial, sin embargo, hasta el momento no existen estudios en nuestro país que lo hayan valorado de manera no invasiva. La importancia de determinar el FC en voluntarios sanos radica en establecer una base para poder comparar estos resultados con los encontrados en pacientes con diferente patología que afecte el flujo coronario. Para la determinación del FC y la reserva de flujo coronario (RFC) y del índice de vasodilatación dependiente de endotelio (IVED) mediante PET se realizan 3 mediciones en 3 fases distintas: reposo, estimulación con frío (CPT) y esfuerzo farmacológico, con la utilización de amonio. Objetivo: Determinar el FC en las tres fases en población sana con la utilización de amonio-PET. Resultados: El FC global basal fue de 0.34 (±0.09) mL/g/min, durante el CPT incrementó a 0.55 (±0.17) mL/g/min y con el estrés llegó a 1.18 (±0.25). La RFC fue de 3.5 (±0.65) y el IVED de 1.55 (±0.33). Conclusiones: Los valores obtenidos de RFC y de IVED en población mexicana sana coincide con los reportados en la literatura. Estos valores representan una base de referencia para las investigaciones futuras con esta tecnología en nuestro país.

Coronary artery disease (CAD) represents the principal cause of morbidity and mortality in our environment. Positron emission tomography (PET) is a new technique in our country that allows the assessment of myocardial perfusion and the absolute quantification of the coronary blood flow (CBF) through the utilization of radiotracers using the same criteria employed in conventional nuclear cardiology. CBF normal values have been determined in other populations around the world. No studies in our country assessing in a non-invasive way the CBF have been published before. The quantification of CBF in healthy population is important to establish a standard measure and determine through it, the effects of the many diseases that change the coronary blood flow. The quantification of the CBF, the calculation of coronary blood flow reserve (CFR) and the endothelium dependent vasodilatation index (EDVI) through PET is possible performing three different acquisition stages: rest, cold pressor test (CPT) and pharmacologic stress using Ammonia as radiotracer. The aim of this study was to evaluate the CBF, the CFR and the EDVI in healthy Mexican volunteers. Results: Global basal CBF was 0.34 (±0.09) mL/g/min, during CPT increased to 0.55 (±0.17) mL/g/min and during the stress increased to 1.18 (±0.25). CFR was 3.5 (±0.65) and EDVI was 1.55 (±0.33). Conclusions: CFR and EDVI values obtained in Mexican healthy population correlates very well with those reported in the literature. This values represents a reference to further research that use this technology.

Change in Coronary Blood Blow and Coronary Blood Flow Reserve after a single High-Fat and Low-Fat Meal in Patients with Ischemic Heart Disease Assessed by Transthoracic Echocardiography

BACKGROUND AND OBJECTIVES: Transient tirglyceridemia decrease vascular reactivity. The aim of this project is to assess the difference in coronary blood flow and coronary blood flow reserve (CFR) after a single High-Fat (HFM) and a Low-Fat meal (LFM) in patients with ischemic heart disease (IHD). METHOD: We included eleven patients with IHD (mean age : 57.2+/-9.5) and excluded significant lesion of left anterior descending artery (more than 60%). We examined blood pressure, pulse rate, blood glucose, total cholesterol, triglyceride, High density lipoprotein-cholesterol (HDL-C) before and 120 minutes after HFM and LFM. Coronary blood flow and CFR of the left anterior descending artery was determined by transthoracic Doppler echocardiography at the same time. Maximal vasodilating activity was obtained 3 to 5 minutes after adenosine infusion at the rate of 140 ug/kg/min. The percentages of total lipid at HFM and LFM were respectively 64% (513 kcal/803 kcal) and 16% (126 kcal/800 kcal). RESULT: Serum triglyceride increased from 153.0+/-78.7 mg/dL preprandially to 228.5+/-95.4 mg/dL after HFM (p<0.01). Serum triglyceride after HFM was higher than after LFM (166.4+/-67.4 mg/dL, p<0.05). Serum glucose increased from 97.2+/-18.8 mg/dL preprandially after LFM and HFM (152.6+/-38.0 mg/dL, 123.8+/-30.8 mg/dL, p<0.05). Serum glucose after LFM was higher than after HFM (p<0.01). The maximal and mean diastolic velocity of coronary flow at fasting (22.5+/-5.5 cm/sec, 17.8+/-4.3 cm/sec) increased after LFM (25.9+/-5.9 cm/sec, 20.2+/-5.3 cm/sec, p<0.01, p<0.05), and not increased after HFM significantly (24.5+/-4.6 cm/sec, 19.5+/-3.3 cm/sec). The CFR was 2.01+/-0.81 at fasting, 1.97+/-0.72 after LFM and 2.05+/-0.58 after HFM. There was no significant diffterence in CFR related to the diet. CONCLUSION: In patient with IHD, CFR may not be affected by HFM and LFM. There was increasing tendency of the coronary blood flow after diet, especially by LFM. This is potential mechanism of postprandial angina.

The Relationship between Change of Cardiac Function and Systemic Oxygen Consumption according to the Dose of Dopamine in the Rabbit

PURPOSE: We'd like to know the relationship between the changes of cardiac function and systemic O2 consumption according to the increasing dose of dopamine. METHODS: Ten rabbits(from 2kg to 2.8kg) were used in this experiment. Anesthesia was induced with intraperitoneal pentobarbital sodium(35mg/kg) and tracheostomy was done. It was maintained by ventilation with a mixture of 1-3% halothane and 67-69% oxygen. Polyvinyl catheters were inserted into the femoral artery and vein and to check blood pressure and arterial blood gas analysis during the surgical procedure. Two other catheters were inserted into the internal carotid artery and external jugular vein and advanced into left ventricle and right atrium to check the pressure of each chamber, LV maximal dP/dt and to obtain blood samples of each chamber. Thoracotomy was done to expose aorta and coronary artery to check the cardiac output and coronary blood flow. We injected dopamine every 10 minutes according to the scheduled dose through external jugular vein and recorded heart rate, cardiac output, aortic pressure, maximal dP/dt, coronary blood flow by computer. Systemic O2 consumption was calculated by Fick method RESULTS: The heart rate and mean aortic pressure increased slowly according to the dose of dopamine from 20 microgram/kg/min. The cardiac otuput the maximal dP/dt and coronary blood flow was not changed until 5 microgram/kg/min, but from 7.5microgram/kg/min, it increased according to the dose of dopamine. CONCLUSION: Dopamine was a powerful inotrophic agent without increasing the systemic O2 consumption until 20microgram/kg/min, but systemic O2 consumption increased markedly at more than 20 microgram/kg/min of dopamine.

Effects of Vasodilators on Coronary Vasospasm Induced by Endothelin in the Isolated Perfused Rat Heart / 대한마취과학회지

BACKGROUND: An endothelium derived vasoconstrictor peptide, endothelin, has been shown to be a potent coronary vascular constrictor. In the clinical settings of angina or myocardial ischemia, the endothelial injury of coronary artery can stimulate the endothelin production. In this study, the authors assessed the response to endothelin of the coronary artery in isolated rat heart and compared the relative effects of three vasodilators (nifedipine, adenosine, nitroprusside) on coronary vasospasm which was induced by endothelin. METHODS: The isolated rat heart preparations (Langendorff model) were obtained from fourty male Sprague-Dawley rats (350-400 gm). Preparations were perfusated with Krebs-Hanseleit solution of (mM): NaCl 115, NaHCO3 25, KCl 4.7, CaCl2 2H2O 2.5, MgCl2 6H2O 1.2, KH2PO4 1.2, glucose 10. The perfusate was maintained at 37oC and aerated with carbogen (oxygen 95% and carbon dioxide 5%). The coronary perfusion was maintained at 80 cmH20 pressure and Latex balloon was positioned in left ventricle. After the preparations were stabilized, endothelin (10(-9) M) was added to perfusate for 5 minutes and followed the perfusion without vasodilators (control, n = 10) or with vasodilators (nifedipine, adenosine and nitroprusside 10(-7) M to 10(-6) M, n = 10 each) for 45 minutes. The left ventricular developed pressure (LDP) and heart rate (HR) was recorded and the coronary effluent (VOL) was collected to measure the unit volume and the CPK isoenzyme (CK-MB). Effects of the interventions were assessed using analysis of variance. All values are presented as means +/- SE. RESULTS: VOL, HR and VDP were significantly reduced after infusion of 10(-9) M endothelin in 3 and 5 minutes. VOL was recovered efficiently after infusion of three vasodilators. Adenosine and nitroprusside groups showed superior recovery in the changes of rate pressure product (RPP) than in nifedipine group, which was significant reduced in VDP. CONCLUSIONS: These results suggest that in the situation of endothelin induced severe coronary vasospasm, adenosine and nitroprusside effectively reversed the coronary vasospasm without severe myocardial depression.

Effect of MPD on Acute Myocardial Ischemia in Dogs / 中药新药与临床药理

Objective To study the protecitve effect of methy Protodioscin(MPD)on myocardial infarction in dogs. Methods Dog models of myocardial infarction were induced by ligation of coronary artery. The degree of myocardial ischemia was calculated by measuring the epicardial electrogram, and the myocardial infarction area was detected with N-BT histochemistry staining method. The changes of ET, 6-Keto-PGF1a, TXB2 in blood plasma were observed with radioimmunoassay. Meanwhile, the coronary blood flow was measured. Results MPD can obviously relieve the pathological changes of the acute myocardial infarction, decrease the infarction size, reduce the myocardium ischemic degree, dilate the coronary artery , and increase the myocardial blood supply. Meanwhile, MPD can improve the vascular endothelial cell function. Conclusion MPD had obvious effect for relieving acute myocardial infarction in dogs.

Coronary Blood Flow Velocity and Coronary Flow Reserve in Normal Left anterior Descending Coronary Arteries

BACKGROUND: Recently, assessment of left anterior descending (LAD) coronary flow by transthorasic Doppler echocardiography (TTDE) has been emerged as a useful tool in evaluation of microcirculatory function of coronary circulation. The measuring site of coronary flow by TTDE is distal LAD. But it was not fully investigated whether the distal flow velocity is identical to that of proximal segment. The purpose of this study is to compare coronary blood flow velocity and coronary flow reserve (CFR) in normal LAD according to its level. METHOD: 9 patients (1 male, 8 females; mean age 52.8+/-11.1years) were included for this study. Coronary flow velocity was measured with intracoronary Doppler guide wire at the proximal (before first diagonal branch), mid (after second diagonal branch), and distal segments of LAD at baseline and after intracoronary bolus injection of 18 microgram adenosine. Baseline and hyperemic average peak velocity (APV) and CFR were compared between segment. RESULTS: Baseline and hyperemic APV appears to be diminished from proximal (24.6+/-3.5 cm/sec, 55.8+/-10.7 cm/sec) to distal (21.7+/-6.9 cm/sec, 49.7+/-17.2 cm/sec) LAD without statistical significance. But, CFR showed no significant difference in each segments (proximal, mid, and distal segment; 2.3+/-0.26, 2.3+/-0.32, 2.3+/-0.48, p=0.95). As the increment of peak systolic velocity (PSV) from baseline to hyperemic state was larger than that of peak diastolic velocity (PDV), diastolic to peak systolic velocity ratio (DSVR) was decreased significantly by hyperemic state in proximal and distal segment (baseline; 2.1+/-0.8, 2.1+/-0.5 vs hyperemia; 1.8+/-0.6, 1.7+/-0.3, p<0.05). CONCLUSION: Coronary blood flow velocity appears to be decreased from proximal to distal segment of normal LAD without statistical significance. There were no differences in CFR between proximal, mid and distal segment of normal LAD.

The Effect of Desflurane on Myocardial Contractility and Coronary Flow in Isolated Rat Hearts / 대한마취과학회지

Background: Desflurane, a fluorinated methyl-ethyl ether, has some advantageous properties including low blood solubility, stability in soda lime, and resistance to biodegradation. Desflurane in vivo has demonstrated myocardial depressant property. The purpose of this study was to test the direct effects of desflurane on myocardial contractile function and coronary flow in the isolated heart. Methods: Twelve isolated rat hearts were continuously perfused with modified Krebs solution containing 6, 9 and 12 vol% of desflurane for 10 min at each concentration. Systolic left ventricular pressure and rate of change of ventricular pressure (dp/dt) were measured. Heart rate and coronary flow were also measured. To differentiate direct vasodilatory effect of desflurane from an indirect metabolic effect due to autoregulation of coronary flow, oxygen delivery, myocardial oxygen consumption and percent oxygen extraction were calculated. Results: Heart rate (control 266+/-22 beats/min) decreased to 250+/-23 beats/min at 6 vol%, 236+/-26 beats/min at 9 vol% and 223+/-22 beats/min at 12 vol% of desflurane. Systolic left ventricular pressure and dp/dt decreased in a concentration-dependent manner. In spite of decrement of myocardial oxygen consumption, coronary flow (control 12.0+/-1.2 ml/min) increased to 12.8+/-1.6 ml/min at 6 vol%, 12.9+/-1.6 ml/min at 9 vol% and 13.7+/-1.4 ml/min at 12 vol% of desflurane. Oxygen delivery increased proportionally with coronary flow. Percent oxygen extraction decreased in a concentration-dependent manner. Conclusion: These results suggest that desflurane has a direct myocardial depressing and coronary vasodilating effect in a concentration-dependent manner.

Myocardial Contrast Echocardiography for the Assessment of Coronary Blood Flow Reserve

BACKGROUND: The assessment of coronary blood flow reserve measured by intracoronary Dopper syudy is a useful method for evaluation of functional impairment of coronary artery disease irrespective of significant anatomic stenosis. To validate the usefullness of myocardial contrast echocardiography in clinical assessment of coronary blood flow reserve, several variables analysed by myocardial contrast echocardiography were compared with coronary flow reserve measured by Dopper catheter study. METHODS: During the coronary angiography, coronary flow reserve was measured by intracoronary Dopper-tipped guidewire with coronary blood flow velocity ratio in 16 patients without angiographically significant coronary artery disease. For the measurement of coronary flow reserve, we analyzed the time-video intensity curve of short axis image of the left ventricle follwing infusion of sonicated hexabrix before and after intracoronary administration of adenosine. RESULTS: 1) There was no significiant difference or correlation between peak intensity, peak intensity ratio, washout time, half time of washout, and washout time ratio analysed by contrast echocardiography and coronary blood flow reserve measured by intracoronary Doppler study(p>0.05). But inverse correlation was observed between half time ratio of contrast washout and coronary flow reserve(r=0.63,p<0.05). 2) There was no significiant difference between non myocardial infarction group and myocardial infartion group in coronary flow reserve and half time ratio of contrast washout. 3) No significant difference was observed before and after administrantion of sonicated hexabrix in hemodynamic variables. CONCLUSION: Among several variables of myocardial contrast echocardiography analysis half time ratio of washout was significantly correlated with coronary flow reserve. Thus assesssment of coronary flow reserve with myocardial contrast echocardiography is promising method in the evaluation of dymamic coronary perfusion and myocardial viability.

Regional Differences of Coronary Blood Flow Dynamics in Angiographically Normal Coronary Artery

BACKGROUND: The characterization of normal coronary blood flow dynamics should provide crucial guidelines for the accurate functional assessment of diseased coronary artery. However, the regional characteristics of coronary blood flow dynamics in normal human coronary artery have not been fully evaluated. METHODS: We performed proximal and distal segment velocity measurement of angiographically normal left anterior descending(LAD) and right coronary artery(RCA) in 25 patients(14 males, 12 females, age 50+/-10 yesre) with atypical chest pain. Spectral flow velocity parameters including average peak velocity(APV), average diastolic peak velocity(ADPV), average systolic peak velocity(ASPV), and diastolic-to-systolic velocity ratio(DSVR) were measured using 0.014 inch 15MHz Doppler wire at baseline and intracoronary adenosine-induced maximal hyperemic state. Coronary flow reserve(CFR) was calculated from the ratio of hyperemia to baseline APV. RESULTS: Comparison between LAD with RCA. LAD showed significantly higher APV than RCA at baseline(proximal ; 18+/-6cm/s vs 14+/-4cm/s, p CFR was significantly lower in LAD than in RCA(proximal ; 301+/-0.9 vs 3.8+/-1.0 , p<3001, and distal ; 3.1+/-0.7 vs 3.6+/-0.8, p<.05). Comparison between proximal with distal segment. There was significant reduction in APV and ASPV from proximal to distal segment in RCA, but not in LAD. There was significant increase in DSVR from proximal to distal segment in RCA, but not in LAD. There was no difference in CFR between proximal and distal segment in both coronary arteries. CONCLUSION: We measured coronary blood flow velocities in angiographically normal coronary artery to characterized normal coronary blood flow dynamics and provide the reference values for the assessment of coronary artery disease. Significant regional differences of coronary blood flow velocities should be considered when we assess the diseased coronary artery.