Nondipping Blood Pressure Patterns Predict Obstructive Sleep Apnea in Patients Undergoing Ambulatory Blood Pressure Monitoring.

A nondipping blood pressure (BP) pattern is common in patients with obstructive sleep apnea (OSA). However, it is unclear how useful a nondipping BP pattern is in screening for OSA. In this cross-sectional study, we recruited consecutive patients with clinical indications for performing ambulatory BP monitoring evaluating the following dipping patterns: (1) normal: ≥10% but <20%; (2) extreme: ≥20%; (3) reduced: ≥0% but <10%; and (4) reverse (riser): <0%. Sleep questionnaires and sleep studies were performed within 7 days after ambulatory BP monitoring. OSA was defined as an apnea-hypopnea index ≥15 events/h. We evaluated 153 patients (OSA frequency, 50.3%). Patients with OSA had higher BPs during sleep, were taking more antihypertensive drugs, and more frequently used hypertensive drugs during the night than patients without OSA. Considering systolic BP, the frequency of OSA in patients with reverse dippers (73.5%) was higher than normal (37.3%), extreme (46.2%), and reduced dippers (49.1%; P=0.012). For diastolic BP, OSA was more common in reduced (66.7%) and reverse dippers (69.6%) as compared to normal (41.4%) or extreme dippers (33.3%; P=0.007). In the regression analysis, reverse systolic dipper was independently associated with OSA (odds ratio, 3.92; 95% CI, 1.31-11.78). Both reduced and reverse diastolic dippers increased the likelihood of OSA for 2.7-fold and 3.5-fold, respectively. Snoring and positive sleep questionnaire findings were associated with a modest increase in the accuracy of reverse dipping pattern for predicting OSA. In conclusion, reverse systolic, as well as reduced and reverse diastolic dippers are independently associated with OSA.

Spironolactone Versus Clonidine as a Fourth-Drug Therapy for Resistant Hypertension The ReHOT Randomized Study (Resistant Hypertension Optimal Treatment)

ABSTRACT: The aim of this study is to compare spironolactone versus clonidine as the fourth drug in patients with resistant hypertension in a multicenter, randomized trial. Medical therapy adherence was checked by pill counting. Patients with resistant hypertension (no office and ambulatory blood pressure [BP] monitoring control, despite treatment with 3 drugs, including a diuretic, for 12 weeks) were randomized to an additional 12-week treatment with spironolactone (12.5-50 mg QD) or clonidine (0.1-0.3 mg BID). The primary end point was BP control during office (<140/90 mm Hg) and 24-h ambulatory (<130/80 mm Hg) BP monitoring. Secondary end points included BP control from each method and absolute BP reduction. From 1597 patients recruited, 11.7% (187 patients) fulfilled the resistant hypertension criteria. Compared with the spironolactone group (n=95), the clonidine group (n=92) presented similar rates of achieving the primary end point (20.5% versus 20.8%, respectively; relative risk, 1.01 [0.55-1.88]; P=1.00). Secondary end point analysis showed similar office BP (33.3% versus 29.3%) and ambulatory BP monitoring (44% versus 46.2%) control for spironolactone and clonidine, respectively. However, spironolactone promoted greater decrease in 24-h systolic and diastolic BP and diastolic daytime ambulatory BP than clonidine. Per-protocol analysis (limited to patients with ≥80% adherence to spironolactone/clonidine treatment) showed similar results regarding the primary end point. In conclusion, clonidine was not superior to spironolactone in true resistant hypertensive patients, but the overall BP control was low (≈21%). Considering easier posology and greater decrease in secondary end points, spironolactone is preferable for the fourth-drug therapy.

Association of obstructive sleep apnea with arterial stiffness and nondipping blood pressure in patients with hypertension.

Whether sex influences the association of obstructive sleep apnea (OSA) with markers of cardiovascular risk in patients with hypertension is unknown. In this study, 95 hypertensive participants underwent carotid-femoral pulse wave velocity, 24-hour ambulatory blood pressure monitoring, echocardiogram, and polysomnography after a 30-day standardized treatment with hydrochlorothiazide plus enalapril or losartan. OSA was present in 52 patients. Compared with non-OSA patients, pulse wave velocity values were higher in the OSA group (men: 11.1±2.2 vs 12.7±2.4 m/s, P=.04; women: 11.8±2.4 vs 13.2±2.2 m/s, P=.03). The proportion of diastolic dysfunction was significant in men and women with OSA. Compared with non-OSA patients, nondipping systolic blood pressure in OSA was higher in men (14.3% vs 46.4%) and in women (41.4% vs 65.2%). OSA was independently associated with pulse wave velocity (ß=1.050; P=.025) and nondipping systolic blood pressure (odds ratio, 3.03; 95% confidence interval, 1.08-8.55; P=.035) in the regression analysis. In conclusion, OSA is independently associated with arterial stiffness and nondipping blood pressure in patients with hypertension regardless of sex.

Successive blood pressure measurements to evaluate suspected and treated hypertension.

INTRODUCTION: According to the published literature, blood pressure (BP) measurements performed in the outpatient clinical setting are often inaccurate. The white coat effect and improper technique are the main causes of this imprecision. Construction of a set of readings without them could improve the accuracy of BP measurement. OBJECTIVE: To evaluate the accuracy and agreement of successive office BP measurements using the awake blood pressure average (ABPa) as the gold standard. METHODS: BP was measured in 852 patients using three techniques: in office (OBPa); seven successive measurements performed by a nurse using an automatic device; and 24 h of ambulatory BP monitoring. BP averages (BPa) were obtained from the nurse's measurements: 1-2BPa (first and second), 3-7BPa (third to seventh), and 1-7BPa (first to seventh). OBPa and successive measurements were tested against ABPa by calculating the following: average difference in BP of 1-2BPa, 3-7BPa and OBPa, and the area under the curve. RESULTS: Among the 834 patients eligible, 374 (43.9%) were considered to be hypertensive on the basis of the ABPa (≥135/85 mmHg). 3-7BPa showed the lowest average difference (4/3 mmHg). By contrast, OBPa showed the highest result (21/11 mmHg). The mean difference with 1-2BPa was 8/4 mmHg. The areas under the curve were better with 3-7BPa (0.82-0.85) and 1-2BPa (0.82-0.83) than OBPa (0.67-0.71) for both systolic and diastolic BP. CONCLUSION: All means from successive measurements showed a better precision than OBPa, even the two first readings. However, more research needs to be carried out before recommendation of the use of this technique in routine practice.

Resistant hypertension optimal treatment trial: a randomized controlled trial.

The prevalence of resistant hypertension (ReHy) is not well established. Furthermore, diuretics, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and calcium channel blockers are largely used as the first 3-drug combinations for treating ReHy. However, the fourth drug to be added to the triple regimen is still controversial and guided by empirical choices. We sought (1) to determine the prevalence of ReHy in patients with stage II hypertension; (2) to compare the effects of spironolactone vs clonidine, when added to the triple regimen; and (3) to evaluate the role of measuring sympathetic and renin-angiotensin-aldosterone activities in predicting blood pressure response to spironolactone or clonidine. The Resistant Hypertension Optimal Treatment (ReHOT) study (ClinicalTrials.gov NCT01643434) is a prospective, multicenter, randomized trial comprising 26 sites in Brazil. In step 1, 2000 patients will be treated according to hypertension guidelines for 12 weeks, to detect the prevalence of ReHy. Medical therapy adherence will be checked by pill count monitoring. In step 2, patients with confirmed ReHy will be randomized to an open label 3-month treatment with spironolactone (titrating dose, 12.5-50 mg once daily) or clonidine (titrating dose, 0.1-0.3 mg twice daily). The primary endpoint is the effective control of blood pressure after a 12-week randomized period of treatment. The ReHOT study will disseminate results about the prevalence of ReHy in stage II hypertension and the comparison of spironolactone vs clonidine for blood pressure control in patients with ReHy under 3-drug standard regimen.

Burnt sugarcane harvesting - cardiovascular effects on a group of healthy workers, Brazil.

BACKGROUND: Brazil is the world's largest producer of sugarcane. Harvest is predominantly manual, exposing workers to health risks: intense physical exertion, heat, pollutants from sugarcane burning. DESIGN: Panel study to evaluate the effects of burnt sugarcane harvesting on blood markers and on cardiovascular system. METHODS: Twenty-eight healthy male workers, living in the countryside of Brazil were submitted to blood markers, blood pressure, heart rate variability, cardiopulmonary exercise testing, sympathetic nerve activity evaluation and forearm blood flow measures (venous occlusion plethysmography) during burnt sugarcane harvesting and four months later while they performed other activities in sugar cane culture. RESULTS: Mean participant age was 31 ± 6.3 years, and had worked for 9.8 ± 8.4 years on sugarcane work. Work during the harvest period was associated with higher serum levels of Creatine Kinase - 136.5 U/L (IQR: 108.5-216.0) vs. 104.5 U/L (IQR: 77.5-170.5), (p = 0.001); plasma Malondialdehyde-7.5 ± 1.4 µM/dl vs. 6.9 ± 1.0 µM/dl, (p = 0.058); Glutathione Peroxidase - 55.1 ± 11.8 Ug/Hb vs. 39.5 ± 9.5 Ug/Hb, (p<0.001); Glutathione Transferase- 3.4±1.3 Ug/Hb vs. 3.0 ± 1.3 Ug/Hb, (p = 0.001); and 24-hour systolic blood pressure - 120.1 ± 10.3 mmHg vs. 117.0 ± 10.0 mmHg, (p = 0.034). In cardiopulmonary exercise testing, rest-to-peak diastolic blood pressure increased by 11.12 mmHg and 5.13 mmHg in the harvest and non-harvest period, respectively. A 10 miliseconds reduction in rMSSD and a 10 burst/min increase in sympathetic nerve activity were associated to 2.2 and 1.8 mmHg rises in systolic arterial pressure, respectively. CONCLUSION: Work in burnt sugarcane harvesting was associated with changes in blood markers and higher blood pressure, which may be related to autonomic imbalance.

Hipertensão arterial sistêmica / Sistemic hypertension

A hipertensão arterial é uma condição clínica caracterizada por elevação da pressão arterial. Ocorre em associação com alterações estruturais e funcionais do coração, cérebro, rins, artérias e veias. Associações de alterações metabólicas com alto risco de eventos cardiovasculares podem ser encontradas na hipertensão.

The effects of continuous positive airway pressure on prehypertension and masked hypertension in men with severe obstructive sleep apnea.

Obstructive sleep apnea and hypertension are common conditions that frequently coexist. Continuous positive airway pressure (CPAP) reduces blood pressure in patients with obstructive sleep apnea and sustained hypertension. However, the impact of CPAP on patients with obstructive sleep apnea and prehypertension and masked hypertension, conditions associated with increased cardiovascular risk, is unknown. Thirty-six male patients (age, 43 ± 7 years; body mass index, 28.8 ± 3.0 kg/m(2)) with untreated severe obstructive sleep apnea (apnea-hypopnea index, 56 ± 22 events/hr on polysomnography) with diagnostic criteria for prehypertension and/or masked hypertension, based on office and 24-hour ambulatory blood pressure monitoring, respectively, were studied. The patients randomized to no treatment (control; n=18) or CPAP (n=18) for 3 months had similar frequency of prehypertension and masked hypertension at study entry. There were no significant changes in blood pressure in patients randomized to the control group. In contrast, patients randomized to CPAP presented significant reduction in office systolic (from 126 ± 5 to 121 ± 7 mm Hg; P=0.001) and a trend for diastolic blood pressure (from 75 ±7 to 73 ± 8 mm Hg; P=0.08) as well as a significant decrease in daytime and nighttime systolic and diastolic blood pressure (P<0.05 for each comparison). There was a significant reduction in the frequency of prehypertension (from 94% to 55%; P=0.02) and masked hypertension (from 39% to 5%; P=0.04) only in the CPAP group. In conclusion, effective CPAP therapy promotes significant reduction in the frequency of prehypertension and masked hypertension by promoting significant blood pressure reductions in patients with severe obstructive sleep apnea.

Obstructive sleep apnea, masked hypertension, and arterial stiffness in men.

BACKGROUND: Obstructive sleep apnea (OSA) is an established cause of hypertension. However, it is not clear whether the frequency of masked hypertension in patients with OSA and whether OSA have an independent role on arterial stiffness taking into account ambulatory blood pressure (BP) monitoring (ABPM). METHODS: We evaluated 61 male normotensive participants as determined by casual clinic BP level <140/90 mm Hg without clinical evidence of cardiovascular disease and on no medications (43 patients with moderate-to-severe OSA (apnea-hypopnea index (AHI) > or = 15 events/hour by polysomnography) and 18 age- and body mass index-matched controls without OSA (AHI <5 events/hour)). Pulse wave velocity (PWV), an index of arterial stiffness, and 24-h ABPM were performed in a blinded fashion. Masked hypertension was defined when abnormal daytime ABPM was > or = 135 or > or = 85 mm Hg. RESULTS: The AHI and lowest oxygen saturation were 2.6 +/- 1.6 and 90 +/- 2 vs. 52.8 +/- 21.0 events/hour and 75 +/- 10% for controls and OSA patients, respectively; P < 0.001. Compared with controls, patients with OSA had higher office systolic BP (113 +/- 9 vs. 118 +/- 10 mm Hg; P = 0.05) and a higher unadjusted proportion of masked hypertension (2 controls (11.1%) vs. 13 patients (30.2%); P < 0.05). PWV was 8.7 +/- 0.7, 9.4 +/- 1.0, and 10.6 +/- 1.1 m/s in the control, OSA without and with masked hypertension groups, respectively (P < 0.01 for each comparison). Multiple regression showed that systolic daytime ABPM and the lowest oxygen saturation were independently related to PWV (adjusted R2 = 0.34; P < 0.01). CONCLUSIONS: Patients with OSA presented a higher unadjusted rate of masked hypertension than matched controls. Lowest oxygen saturation has an independent association with arterial stiffness.

Monitorização materno-fetal durante procedimento odontológico em portadora de cardiopatia valvar / Maternal-fetal monitoring during dental procedure in patients with heart valve disease / Monitoreo maternofetal durante procedimiento odontológico en portadora de cardiopatía valvular

FUNDAMENTO: Os efeitos da anestesia local em odontologia com lidocaína e epinefrina, sobre parâmetros cardiovasculares de gestantes portadoras de valvopatias e seus conceptos, não estão esclarecidos. OBJETIVO: Avaliar e analisar parâmetros da cardiotocografia, de pressão arterial e eletrocardiográficos da gestante portadora de doença valvar reumática, quando submetida à anestesia local com 1,8 ml de lidocaína 2 por cento sem vasoconstritor e com epinefrina 1:100.000, durante procedimento odontológico restaurador. MÉTODOS: Realizamos monitorização ambulatorial da pressão arterial, eletrocardiografia ambulatorial materna e cardiotocografia de 31 portadoras de cardiopatia reumática, entre a 28ª e 37ª semana de gestação, divididas em dois grupos conforme presença ou não do vasoconstritor RESULTADOS: Demonstrou-se redução significativa dos valores de frequência cardíaca materna nos dois grupos, durante o procedimento, quando comparado aos demais períodos (p < 0,001). Houve ocorrência de arritmia cardíaca em 9 (29,0 por cento) pacientes, das quais 7 (41,8 por cento) pertencentes ao grupo de 17 gestantes que recebeu anestesia com adrenalina. A pressão arterial materna não apresentou diferença quando comparamos períodos ou grupos (p > 0,05). O mesmo ocorreu (p > 0,05) com número de contrações uterinas, nível e variabilidade da linha de base e número de acelerações da frequência cardíaca fetal. CONCLUSÃO: O uso de 1,8 ml de lidocaína 2 por cento associado à adrenalina mostrou-se seguro e eficaz em procedimento odontológico restaurador durante a gestação de mulheres com cardiopatia valvar reumática.

BACKGROUND: The effects of local dental anesthesia with lidocaine and epinephrine on cardiovascular parameters of pregnant women with heart valve diseases and their fetuses are not fully understood. OBJECTIVES: To assess and analyze cardiotocographic, blood pressure and electrocardiographic parameters of pregnant women with rheumatic heart valve disease undergoing local anesthesia with 1.8mL of lidocaine 2 percent with or without epinephrine 1:100,000 during restorative dental treatment. METHODS: Maternal ambulatory blood pressure and electrocardiographic monitoring as well as cardiotocography of 31 patients with rheumatic heart disease were performed between the 28th and 37th week of gestation. The patients were divided into two groups, those with or without vasoconstrictor. RESULTS: A significant reduction in maternal heart rate was shown in both groups during the procedure in comparison with the other periods (p<0.001). Cardiac arrhythmia was observed in nine (29.0 percent) patients, of which seven (41.8 percent) were from the group of 17 pregnant women who received anesthesia plus epinephrine. No difference in maternal blood pressure was observed when periods or groups were compared (p>0.05). The same occurred (p>0.05) with the number of uterine contractions, baseline level and variability, and number of accelerations of fetal heart rate. CONCLUSION: The use of 1.8mL of lidocaine 2 percent in combination with epinephrine was safe and efficient in restorative dental procedures during pregnancy in women with rheumatic heart valve disease.

FUNDAMENTO: Los efectos de la anestesia local en odontología con lidocaína y epinefrina, sobre los parámetros cardiovasculares de gestantes portadoras de valvulopatías y sus conceptos, no son claros. OBJETIVO: Evaluar y analizar parámetros de la cardiotocografía, de la presión arterial y electrocardiográficos de la gestante portadora de enfermedad valvular reumática, al someterse a anestesia local con 1,8 ml de lidocaína 2 por ciento sin vasoconstrictor y con epinefrina 1:100.000, durante procedimiento odontológico restaurador. MÉTODOS: Realizamos monitoreo ambulatorio de la presión arterial, electrocardiografía ambulatoria materna y cardiotocografía de 31 portadoras de cardiopatía reumática, entre la 28ª y la 37ª semana de gestación, divididas en dos grupos según la presencia o no del vasoconstrictor. RESULTADOS: Se observó reducción significativa de los valores de frecuencia cardíaca materna en los dos grupos, durante el procedimiento, al compararlo con los demás períodos (p < 0,001). Se registró ocurrencia de arritmia cardíaca en 9 (29,0 por ciento) pacientes, de las cuales 7 (41,8 por ciento) pertenecían al grupo de 17 gestantes que recibió anestesia con adrenalina. La presión arterial materna no presentó diferencia al comparar períodos o grupos (p > 0,05). Lo mismo ocurrió (p > 0,05) con el número de contracciones uterinas, nivel de variabilidad de la línea de base y número de aceleraciones de la frecuencia cardíaca fetal. CONCLUSIÓN: El uso de 1,8 ml de lidocaína 2 por ciento asociado a la adrenalina se mostró seguro y eficaz en procedimiento odontológico restaurador durante la gestación de mujeres con cardiopatía valvular reumática.

Maternal-fetal monitoring during dental procedure in patients with heart valve disease.

BACKGROUND: The effects of local dental anesthesia with lidocaine and epinephrine on cardiovascular parameters of pregnant women with heart valve diseases and their fetuses are not fully understood. OBJECTIVES: To assess and analyze cardiotocographic, blood pressure and electrocardiographic parameters of pregnant women with rheumatic heart valve disease undergoing local anesthesia with 1.8mL of lidocaine 2% with or without epinephrine 1:100,000 during restorative dental treatment. METHODS: Maternal ambulatory blood pressure and electrocardiographic monitoring as well as cardiotocography of 31 patients with rheumatic heart disease were performed between the 28th and 37th week of gestation. The patients were divided into two groups, those with or without vasoconstrictor. RESULTS: A significant reduction in maternal heart rate was shown in both groups during the procedure in comparison with the other periods (p<0.001). Cardiac arrhythmia was observed in nine (29.0%) patients, of which seven (41.8%) were from the group of 17 pregnant women who received anesthesia plus epinephrine. No difference in maternal blood pressure was observed when periods or groups were compared (p>0.05). The same occurred (p>0.05) with the number of uterine contractions, baseline level and variability, and number of accelerations of fetal heart rate. CONCLUSION: The use of 1.8mL of lidocaine 2% in combination with epinephrine was safe and efficient in restorative dental procedures during pregnancy in women with rheumatic heart valve disease.

Silent myocardial ischemia in patients with stable coronary artery disease receiving conventional antianginal drug therapy.

BACKGROUND: Few data are available on the behavior of myocardial ischemia during daily activities in patients with coronary artery disease receiving antianginal drug therapy. OBJECTIVE: To study the mechanism generating myocardial ischemia by evaluating blood pressure and heart rate changes in patients with stable atherosclerotic disease receiving drug therapy and with evidence of myocardial ischemia. METHODS: Fifty non-hospitalized patients (40 males) underwent 24-hour electrocardiographic monitoring synchronized with blood pressured monitoring. RESULTS: Thirty five episodes of myocardial ischemia were detected in 17 patients, with a total duration of 146.3 minutes; angina was reported in five cases. Twenty nine episodes (100.3 minutes) occurred during wakefulness, with 11 episodes (35.3 + 3.7 min) in the period from 11 a.m. to 3 p.m. Blood pressure and heart rate evaluation in the three ten-minute intervals following the ischemic episodes showed a statistically significant difference (p< 0.05), unlike that shown for the three intervals preceding the episodes. However, during the ischemic episode, a higher than 10-mmHg elevation in blood pressure and 5 beats per minute in heart rate were observed when compared with the time interval between 20 and 10 minutes before the episode. The mean heart rate at the onset of ischemia during the exercise test performed before the study was 118.2 + 14.0, and 81.1 + 20.8 beats per minute on the 24-hour electrocardiogram (p < 0.001). CONCLUSION: The incidence of silent myocardial ischemia is high in stable coronary artery disease and is related to alterations in blood pressure and heart rate, with different thresholds for ischemia for the same patient.

Isquemia silenciosa na doença coronariana estável em vigência de tratamento medicamentoso / Silent myocardial ischemia in patients with stable coronary artery disease receiving conventional antianginal drug therapy

FUNDAMENTO: Existem poucos dados sobre comportamento da isquemia miocárdica às atividades habituais na vigência da medicação em pacientes com doença coronariana. OBJETIVO: Estudar mecanismo gerador da isquemia miocárdica avaliando-se o comportamento da pressão arterial e da freqüência cardíaca em pacientes com doença aterosclerótica estável, medicados e com evidência de isquemia. MÉTODOS: Cinqüenta pacientes (40 homens) realizaram ambulatorialmente por 24 horas a monitorização eletrocardiográfica sincronizada com a monitorização da pressão arterial. RESULTADOS: Em 17 pacientes detectaram-se 35 episódios de isquemia miocárdica, com duração total de 146,3 minutos, ocorrendo relato de angina em cinco casos. Houve 29 episódios (100,3 minutos) durante o período de vigília, com 11 episódios (35,3+3,7 min) no período das 11 às 15 horas. A avaliação da pressão arterial e freqüência cardíaca nos três intervalos de 10 minutos posteriores ao momento de isquemia mostrou diferença estatisticamente significante (p<0,05), o que não ocorreu nos três intervalos anteriores. Entretanto, durante o momento isquêmico, percebeu-se elevação maior que 10 mmHg da pressão arterial e de cinco batimentos por minuto da freqüência cardíaca quando comparado ao intervalo de tempo entre 20 e 10 minutos anterior. A freqüência cardíaca média no início da isquemia durante teste ergométrico prévio ao estudo foi de 118,2+14,0, e de 81,1+20,8 batimentos por minuto na eletrocardiografia de 24 horas (p<0,001). CONCLUSÃO: A incidência de isquemia silenciosa é freqüente na doença coronária estável, relacionando-se com alterações da pressão arterial e da freqüência cardíaca, com diferentes limiares de isquemia para o mesmo paciente.

BACKGROUND: Few data are available on the behavior of myocardial ischemia during daily activities in patients with coronary artery disease receiving antianginal drug therapy. OBJECTIVE: To study the mechanism generating myocardial ischemia by evaluating blood pressure and heart rate changes in patients with stable atherosclerotic disease receiving drug therapy and with evidence of myocardial ischemia. METHODS: Fifty non-hospitalized patients (40 males) underwent 24-hour electrocardiographic monitoring synchronized with blood pressured monitoring. RESULTS: Thirty five episodes of myocardial ischemia were detected in 17 patients, with a total duration of 146.3 minutes; angina was reported in five cases. Twenty nine episodes (100.3 minutes) occurred during wakefulness, with 11 episodes (35.3 + 3.7 min) in the period from 11 a.m. to 3 p.m. Blood pressure and heart rate evaluation in the three ten-minute intervals following the ischemic episodes showed a statistically significant difference (p< 0.05), unlike that shown for the three intervals preceding the episodes. However, during the ischemic episode, a higher than 10-mmHg elevation in blood pressure and 5 beats per minute in heart rate were observed when compared with the time interval between 20 and 10 minutes before the episode. The mean heart rate at the onset of ischemia during the exercise test performed before the study was 118.2 + 14.0, and 81.1 + 20.8 beats per minute on the 24-hour electrocardiogram (p < 0.001). CONCLUSION: The incidence of silent myocardial ischemia is high in stable coronary artery disease and is related to alterations in blood pressure and heart rate, with different thresholds for ischemia for the same patient.

Effects of epinephrine in local dental anesthesia in patients with coronary artery disease.

BACKGROUND: The use of vasoconstrictors for local anesthesia in patients with coronary heart disease is controversial in the literature, and there is concern regarding risk of cardiac decompensation. OBJECTIVE: To evaluate electrocardiographic and blood pressure parameters during restorative dental procedure under local anesthesia with and without a vasoconstrictor in patients with coronary artery disease. METHODS: Sixty-two patients were included in the study, ages ranging from 39 to 80 (mean 58.7 +/- 8.8), 51 (83.2%) of whom were male. Thirty patients were randomly assigned to receive 2% lidocaine with epinephrine (epinephrine group), and the remaining patients, 2% lidocaine without epinephrine (non-epinephrine group) for local anesthesia. All patients underwent 24-hour ambulatory blood pressure monitoring and dynamic electrocardiography. Three periods were considered in the study: 1) baseline--recordings obtained during the 60 minutes prior to the procedure; 2) procedure--recordings obtained from the beginning of anesthesia to the end of the procedure and 3) 24 hours. RESULTS: There was an increase in blood pressure in both groups during the procedure, compared with baseline values; but when the two groups were compared no significant difference was detected between them. Heart rate remained unchanged in both groups. No ST-segment depression > 1 mm occurred either at baseline or during the procedure. Seven patients (12.5%) experienced more than ten arrhythmia episodes per hour during the procedure, four (13.8%) in the non-epinephrine group and three (11.1%) in the epinephrine group. CONCLUSION: No difference was observed in blood pressure, heart rate, or evidence of ischemia and arrhythmias in either group. The use of vasoconstrictor has proved to be safe within the range of the present study.