An emergency physician activated protocol, 'Code STEMI' reduces door-to-balloon time and length of stay of patients presenting with ST-segment elevation myocardial infarction.

INTRODUCTION: National consensus guidelines recommend that ST-segment elevation myocardial infarction (STEMI) patients achieve a door-to-balloon time of < 90 min. We sought to determine if emergency physician initiated simultaneous activation of the cardiac catheterisation laboratory team and the on-call interventional cardiologist has any impact on reducing door-to-balloon-times at our hospital. METHODS: A total of 72 consecutive STEMI patients were evaluated from January 2007 to December 2007. The emergency physician activated Code STEMI required concurrent activation of cardiac catheterisation personnel and the on-call interventional cardiologist by the emergency physician. These patients were compared with our staff cardiologist activated primary angioplasty protocol from January 2006 to December 2006 for 51 consecutive STEMI patients. The primary outcome was to measure median door-to-balloon time between both groups. Secondary end-points included the individual components of door-to-balloon times (i.e. door-to-ECG time), peak troponin-I level within 24 h, length of stay and all-cause in-hospital mortality. RESULTS: Median door-to-balloon time decreased overall (112 vs. 74 min, p < 0.001). Of the three components of door-to-balloon time analysed, the ECG to cardiac catheterization laboratory time exhibited the largest area of improvement with 16 min absolute reduction in median door-to-balloon time. Median peak troponin levels (50 vs. 25 ng/ml, p < 0.001), and hospital length of stay (4 vs. 3 days, p < 0.01) decreased. We did not see any statistically significant difference in all-cause in-hospital mortality (p = 0.6). CONCLUSIONS: Emergency physician activation of the Code STEMI significantly reduces door-to-balloon time to within national standards of care, and length of stay in STEMI patients.

Left ventricular mass and systolic function in human immunodeficiency virus-infected patients after weight loss.

Transthoracic echocardiography was performed on 27 patients with human immunodificiency virus after weight loss and in 20 lean controls. Left ventricular mass index was significantly higher and left ventricular fractional shortening was significantly lower in patients with human immunodificiency virus after weight loss than in lean, normal controls.

Factors predicting coronary artery disease in patients with giant negative T waves.

Seventy-four patients with giant negative T waves were studied to determine which electrocardiographic variables predicted the presence of coronary artery disease. The absence of left ventricular hypertrophy and the presence of symmetric T-wave inversion predicted coronary artery disease.

Diminished short-term heart rate variability predicts inducible ventricular tachycardia.

PURPOSE: The purpose of this study is to determine whether short-term heart rate variability (HRV) can be used successfully to predict inducible ventricular tachycardia (VT). METHODS: A high-speed (300 mm/s) electrocardiographic recording was obtained in 32 patients in the supine position prior to programmed ventricular stimulation. Beat-to-beat RR intervals (in milliseconds) were derived from an 11-beat strip (10 RR intervals). Logistic regression was used to study the relationship between several variables and a dichotomous dependent variable (inducible, clinical, or electrocardiographic evidence of VT). RESULTS: Of 32 patients, 12 had inducible VT (inducible VT group) and 20 had no clinical or electrocardiographic evidence of VT (control group). Mean short-term HRV values were significantly lower in those with inducible VT than in the control group in all patients (25+/-15 ms, n=12 vs 67+/-22 ms, n=20; p<0.0001) and in patients with coronary artery disease or congestive heart failure or both (22+/-13 ms, n=11 vs 63+/-23 ms, n=11; p<0.0001). For the group as a whole, short-term HRV was < or =50 ms in 11 of 12 patients (92%) with inducible VT, but was < or =50 ms in only 3 of 20 control subjects (15%; p<0.001). As a result of a stepwise selection procedure conducted within the logistic regression, only the short-term HRV was found to be predictive of inducible VT (p<0.0001). CONCLUSION: Short-term HRV is significantly lower in subjects with inducible VT than in those without clinical or electrocardiographic evidence of VT. The probability of developing sudden death increases substantially when short-term HRV decreases below 50 ms.

New sheath for vascular access and subcutaneous drug administration: multicenter clinical trial for pain prevention after cardiac catheterization.

A new vascular sheath design (anesthesia infusion sleeve, or AIS) was developed to enable administration of local anesthetics or other medications into the subcutaneous tissue around an arterial or venous insertion site without any additional needle sticks or manipulation. Design, animal testing, and an initial small single-site clinical study have previously been published. The current study was multicenter and randomized 80 patients to use of a standard sheath for vascular access or the AIS. Pain associated with sheath placement, postprocedure pain, and pain associated with sheath removal before and during manual compression was recorded. Baseline pain was identical in both the standard and AIS groups. Pain during infiltration and with initial femoral artery compression was significantly lower in the AIS group. A quality of life questionnaire indicated that the AIS sheath was associated with less discomfort and was preferred over a standard sheath in patients who had had a previous procedure performed. The AIS represents a simple addition to standard sheath design, offering superior pain control during removal compared to the standard technique, without the need for systemic analgesics or additional needle punctures.

Effects of intracoronary carbon dioxide on left ventricular function in swine.

BACKGROUND AND HYPOTHESIS: Carbon dioxide is currently used as an arterial and venous contrast agent; however, little is known of its effects on left ventricular function. This study was undertaken to investigate those effects. METHODS: Ascending doses of 5, 10, and 20 ml of carbon dioxide were administered into the left main coronary artery of domestic swine with and without a continuous infusion of intravenous nitroglycerin (50 micrograms/min). RESULTS: Carbon dioxide had an immediate and profound depressant effect on both systolic and diastolic left ventricular function associated with ischemic electrocardiographic changes. Compared with controls (% change), ascending doses of carbon dioxide decreased systolic pressure by -35 +/- 7, -48 +/- 8, and -53 +/- 4 in the absence of nitroglycerin, and by -32 +/- 9, -50 +/- 9, and -60 +/- 9 in the presence of nitroglycerin. Peak+dP/dt decreased by -54 +/- 7, -61 +/- 11, and -64 +/- 3 in the absence of nitroglycerin, and by -36 +/- 13, -55 +/- 11, and -65 +/- 11 in the presence of nitroglycerin. Minimum -dP/dt increased by 65 +/- 8,71 +/- 8, and 77 +/- 3 in the absence of nitroglycerin, and by 63 +/- 7,71 +/- 8, and 78 +/- 7 in the presence of nitroglycerin. No significant changes in heart rate were observed; however, widespread ST-segment elevation was observed in all animals. Coronary angiography following carbon dioxide injection revealed a marked decrease in coronary flow velocity until the gas was cleared from the microcirculation. This was also documented by direct measurement of flow velocity using a Doppler catheter in an additional animal. Left ventriculography demonstrated immediate global dilation and depression of systolic function. CONCLUSIONS: In the swine model, relatively small doses of intracoronary carbon dioxide cause profound yet reversible global left ventricular dysfunction which appears to be ischemic in origin.

New vascular sheath for subcutaneous drug administration: design, animal testing, and clinical application for pain prevention after angioplasty.

A new vascular sheath design (anesthesia infusion sleeve or AIS) was developed to enable administration of local anesthetics or other medications into the subcutaneous tissue around the insertion site without any additional needle sticks or other manipulation. Design of the system was based upon anatomic measurements of femoral artery depth in 150 patients. Animal studies of prototypes verified subcutaneous delivery using both radiographic methods and direct dissection. The pharmacokinetic profile of plasma lidocaine was also studied in three pigs to document subcutaneous delivery with the AIS. Subsequently a clinical trial of the AIS versus a standard sheath was done in 20 patients undergoing coronary angioplasty. Pain associated with sheath removal was graded using a verbal scale at baseline, during infiltration of the area, and at 1-min intervals during compression for 15 min. Baseline pain was identical in both groups, whereas, during infiltration with lidocaine, pain increased in the standard sheath group and decreased in the AIS group. Pain increased slightly in both groups with initial compression; however, it was significantly less in the AIS group. This difference persisted for several minutes after initial compression. The AIS represents a simple addition to standard sheath protocol offering superior pain control compared to standard technique for sheath removal without the need for systemic analgesics or other medications.

A closed-chest porcine model of coronary dissection and thrombosis.

BACKGROUND: Coronary dissection and thrombosis are important as pathophysiological mechanisms in acute coronary syndromes and as consequences of various interventional procedures. The present study was designed to develop and characterize a simple percutaneous method to produce coronary dissection and thrombosis in the pig. METHODS: The porous balloon (Wolinski type) was slightly oversized (balloon-to-artery ratio, 1.21 +/- 0.08) and placed in the left anterior descending artery in 12 domestic pigs using standard percutaneous techniques. The balloon was inflated using a pressure-activated syringe at 5 atm to deliver 1 ml of either saline or a small amount of bovine thrombin (500 units) in saline. The balloon was withdrawn, serial angiograms recorded, and ECG and aortic pressure were monitored throughout. At coronary occlusion or at 30 min, the hearts were removed and fixed for histological analysis. RESULTS: Seven pigs received thrombin and five received saline. On microscopic examination the internal elastic lamina was disrupted in all arteries in both groups. Subintimal and medial dissection was noted in 80% of arterial cross sections in the saline group, and 86% in the thrombin group. Partial occlusion of the coronary artery with thrombus was seen in 20% of samples in the saline group and in 43% of the thrombin group. Thrombus with complete occlusion of the coronary artery was observed in 86% of thrombin-treated vessels but in none of the arteries that received saline. Complete occlusion was observed at 28 +/- 9 min by angiography. CONCLUSIONS: Percutaneous delivery of a small amount of thrombin through a slightly oversized porous balloon catheter produces coronary dissection and thrombosis in a more reproducible and timely fashion than previously described methods. This model may be useful for testing interventional and pharmacologic treatment strategies.

Prevalence of intraatrial thrombus in patients with atrial flutter.

In summary, left atrial thrombus occurs with disproportionately high frequency in patients hospitalized with atrial flutter. Male gender and a left ventricular ejection fraction < 40% are predictors of left atrial thrombus formation in such patients.

Functional characteristics of a new coronary perfusion balloon: comparison with the Flowtrack 40 in closed chest swine.

This study was designed to compare a new investigational coronary perfusion balloon (Wave, Scimed Life Systems Inc.) with that of an approved, widely used, current generation device (Flowtrack 40, Advanced Cardiovascular Systems). Domestic swine were anesthetized with pentobarbital and instrumented using standard percutaneous technique. Left ventricular contractile function (dP/dt) was monitored using a micromanometer while intracoronary and surface ECGs were also recorded. Eight target vessels were studied (4 LAD and 4 Cx) in random order. The perfusion balloons were kept inflated for 10 min. Complete coronary occlusion with a standard angioplasty balloon produced marked decreases in mean aortic pressure, left ventricular developed pressure, peak +dP/dt, peak -dP/dt, and significant ST segment elevation in both intracoronary and surface ECG at 30 seconds. Neither the Wave or Flowtract 40 produced any change in heart rate or mean aortic pressure. Both catheters caused a drop in left ventricular developed pressure immediately after balloon inflation. At 10 min, however, there was a small but significant decrease only with the Flowtrack 40. Similarly, peak +dP/dt was slightly depressed during Flowtrack 40 inflation at 10 min but not with the Wave catheter. Both catheters produced ST segment elevation on the surface and intracoronary electrocardiographic records. These changes were significantly greater with the Flowtrack 40 system. Thus, both the Flowtrack 40 and Wave perfusion balloons are effective in preventing ischemia during coronary occlusion in swine; however, the latter system may be more effective in this model.

Pathogenesis, recognition, and management of common cardiac arrhythmias. Part I: Ventricular premature beats and tachyarrhythmias.

Cardiac arrhythmias are disorders of impulse formation, impulse conduction, or both. Part I of this two-part review discusses clinically relevant cardiac electrophysiology, as well as the pathogenesis, recognition, and management of ventricular premature beats and ventricular tachyarrhythmias. Part II will review the pathogenesis, recognition, and management of supraventricular premature beats and supraventricular tachyarrhythmias.

Left ventricular mass and risk of stroke in an elderly cohort. The Framingham Heart Study.

OBJECTIVE: To evaluate the association of echocardiographically determined left ventricular mass (LVM) with incidence of stroke or transient ischemic attack in an elderly cohort. DESIGN: Cohort study with a follow-up period of 8 years. SETTING: Population-based sample. SUBJECTS: Elderly original cohort subjects of the Framingham Heart Study who were free of cerebrovascular disease and atrial fibrillation at the 16th biennial examination and who had adequate echocardiograms. This group consisted of 447 men (mean age, 67.8 years; range, 60 to 90 years) and 783 women (mean age, 69.2 years; range 59 to 90 years). MAIN OUTCOME MEASURES: Age-adjusted 8-year incidence of stroke was examined as a function of baseline quartiles of LVM-to-height ratio. Proportional hazards regression was used in multivariate analyses to assess risk of stroke as a function of LVM-to-height ratio quartile, adjusting for age, sex, systolic blood pressure, hypertension treatment, diabetes, cigarette smoking, and blood lipid levels. RESULTS: Among the 1230 subjects eligible, 89 cerebrovascular disease events (62 strokes and 27 transient ischemic attacks) occurred during follow-up. In men, 8-year age-adjusted incidence of cerebrovascular events was 18.4% in the highest quartile of LVM-to-height ratio and 5.2% in the lowest quartile. Corresponding values in women were 12.2% and 2.9%. The hazard ratio for cerebrovascular events comparing highest to lowest quartile of LVM-to-height ratio was 2.72 (95% confidence interval [CI], 1.39 to 5.36) after adjusting for age, sex, systolic blood pressure, hypertension treatment, diabetes, cigarette smoking, and the ratio of total cholesterol to high-density lipoprotein cholesterol. After adjusting for age, sex, and cardiovascular disease risk factors, the hazard ratio for cerebrovascular events was 1.45 (95% CI, 1.17 to 1.80) for each quartile increment of LVM-to-height ratio. CONCLUSIONS: Echocardiographically determined LVM-to-height ratio offers prognostic information beyond that provided by traditional cerebrovascular disease risk factors. Echocardiography provides information that facilitates identification of individuals at high risk for stroke and transient ischemic attack.

Asymptomatic ventricular arrhythmias and mortality risk in subjects with left ventricular hypertrophy.

OBJECTIVES: The purpose of this study was to evaluate the long-term prognostic role of asymptomatic ventricular arrhythmias in original Framingham Heart Study subjects and Framing-ham Offspring Study subjects who had echocardiographic evidence of left ventricular hypertrophy. BACKGROUND: Echocardiographically determined left ventricular hypertrophy is associated with increased risk for ventricular arrhythmias. There are no population-based data available with regard to the long-term prognostic implications of asymptomatic ventricular arrhythmias in subjects with left ventricular hypertrophy. METHODS: In a population-based cohort study, we studied 224 men and 393 women with echocardiographically determined left ventricular hypertrophy who were free of coronary heart disease and had 1-h ambulatory electrocardiograms at the baseline examination. The age-adjusted prevalence of complex or frequent ventricular arrhythmias (> 30 ventricular premature beats/h, multiform premature complexes, couplets, ventricular tachycardia or R on T ventricular premature complexes) was 28% (51 of 224) in men and 17% (71 of 393) in women. The mean follow-up period was 5.7 years for cohort and 4.5 years for offspring subjects. RESULTS: In men with complex or frequent arrhythmias, the 6-year cumulative incidence of all-cause mortality was 38%, whereas in those free of arrhythmia it was 12%; corresponding values in women were 22% and 11%. The cumulative incidence of myocardial infarction or death due to coronary heart disease was 20% for men with and 10% for men without arrhythmia, but in women little difference was noted (5% vs. 4%). After adjustment for age and gender in a Cox proportional hazards model, subjects with complex or frequent arrhythmia were at increased risk for all-cause mortality (hazard ratio 1.80, 95% confidence interval [CI] 1.13 to 2.87, p = 0.013). After adjusting for eight clinical covariates, the increased risk for all-cause mortality remained marginally significant (hazard ratio 1.62, 95% CI 0.98 to 2.68, p = 0.058). No significant increased risk was noted for myocardial infarction or death due to coronary heart disease. CONCLUSIONS: In subjects with left ventricular hypertrophy, the presence of asymptomatic ventricular arrhythmias was associated with higher mortality, which was statistically significant after adjusting for age and gender and marginally significant after taking into account other covariates.

Prognostic implications of asymptomatic ventricular arrhythmias: the Framingham Heart Study.

OBJECTIVE: To evaluate the prevalence and prognostic significance of asymptomatic complex or frequent ventricular premature beats detected during ambulatory electrocardiographic (ECG) monitoring. DESIGN: Cohort study with a follow-up period of 4 to 6 years. SETTING: Population-based. PARTICIPANTS: Surviving patients of the original Framingham Heart Study cohort and offspring of original cohort members (2727 men and 3306 women). MEASUREMENTS: One-hour ambulatory electrocardiography. RESULTS: The age-adjusted prevalence of complex or frequent arrhythmia (more than 30 ventricular premature complexes per hour or multiform premature complexes, ventricular couplets, ventricular tachycardia, or R-on-T ventricular premature complexes) was 12% (95% Cl, 11% to 13%) in the 2425 men without clinically evident coronary heart disease and 33% (Cl, 24% to 42%) in the 302 men with coronary heart disease. The corresponding values in women (3064 without disease and 242 with disease) were 12% (Cl, 11% to 13%) and 26% (Cl, 9% to 43%). After adjusting for age and traditional risk factors for coronary heart disease in a Cox proportional hazards model, men without coronary heart disease who had complex or frequent ventricular arrhythmias were at increased risk for both all-cause mortality (relative risk, 2.30; Cl, 1.65 to 3.20) and the occurrence of myocardial infarction or death from coronary heart disease (relative risk, 2.12; Cl, 1.33 to 3.38). In men with coronary heart disease and in women with and without coronary heart disease, complex or frequent arrhythmias were not associated with an increased risk for either outcome. CONCLUSIONS: In men who do not have clinically apparent coronary heart disease, the incidental detection of ventricular arrhythmias is associated with a twofold increase in the risk for all-cause mortality and myocardial infarction or death due to coronary heart disease. The preventive and therapeutic implications of these findings await further investigation.

[Effect of cortisol, adrenaline and ACTH on the absorption and intracellular distribution of protein-labelled lipoproteins by rat liver and adrenal tissues]. / Vliianie kortizola, adrenalina i AKTG na pogloshchenie i vnutrikletochnoe raspredelenie mechennykh po belku lipoproteidov tkaniami pecheni i nadpochechnikov krys.

One hour incubation of slices prepared from rat liver or adrenal glands with 125I labeled lipoproteins of different classes resulted in label binding and its penetration into the tissue cells. The greatest amounts of labeling were found in fractions of mitochondria, lysosomes, microsomes and the final supernatant. In relation to the weight unit, slices from adrenal glands consumed several times as much label as did liver slices. Epinephrine increased the amount of the label bound to the low density lipoproteins by several times in the fractions of large cell membranes, and decreased the 125I level in mitochondria. Cortizole increased the incorporation of the protein labeled lipoproteins very low density into the liver mitochondria. ACTH did not influence the incorporation or cellular distribution of the label in adrenal glands.