RESUMO
To study the safety and feasibility of abruptly changing antianginal therapy from propranolol hydrochloride to verapamil, we gave propranolol to ten patients with stable angina and coronary artery disease for 14 days, then, on day 15, we began verapamil therapy, which continued for 14 more days. Anginal frequency and nitroglycerin use were similar throughout the study. No patient had symptomatic bradycardia or atrioventricular block. Such crossover therapy is effective when propranolol is replaced by verapamil abruptly.
Assuntos
Angina Pectoris/tratamento farmacológico , Propranolol/uso terapêutico , Verapamil/uso terapêutico , Angina Pectoris/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Propranolol/efeitos adversos , Fatores de Tempo , Verapamil/efeitos adversosRESUMO
To compare a propranolol-verapamil with a propranolol-nifedipine combination in patients with severe angina of effort, 16 patients (11 men and 5 women, aged 56 +/- 8 years [mean +/- standard deviation]) with more than 5 episodes/week of angina and a positive exercise tolerance test despite propranolol (229 +/- 44 mg/day [range 180 to 360]) were maintained on this dose of propranolol and, in addition, received verapamil (360 mg/day) and nifedipine (60 mg/day) for 3 weeks each in a double-blind, randomized fashion. In comparison with propranolol alone, anginal frequency and nitroglycerin usage were reduced by propranolol-verapamil but not by propranolol-nifedipine. Exercise time (standard Bruce protocol) was similar for the 2 combinations (6.4 +/- 2.0 minutes with propranolol-verapamil, 6.6 +/- 2.1 minutes with propranolol-nifedipine, difference not significant), but the magnitude of ST-segment depression at peak exercise was less (p less than 0.05) during propranolol-verapamil (0.03 +/- 0.06 mV) than during propranolol alone (0.18 +/- 0.07 mV) and propranolol-nifedipine (0.08 +/- 0.07 mV). Left ventricular ejection fraction at rest was higher (p less than 0.05) with propranolol-nifedipine (0.62 +/- 0.10) than with propranolol-verapamil (0.58 +/- 0.10), but neither differed from ejection fraction at rest with propranolol alone (0.59 +/- 0.08). Ejection fraction at peak exercise was similar during all 3 periods. In 2 patients, verapamil caused weakness, lightheadedness, and severe sinus bradycardia (40 to 48 beats/min), and the dosage was reduced (blindly) to 240 mg/day, with the alleviation of bradycardia and associated symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Angina Pectoris/tratamento farmacológico , Nifedipino/uso terapêutico , Propranolol/uso terapêutico , Verapamil/uso terapêutico , Angina Pectoris/diagnóstico por imagem , Angina Pectoris/fisiopatologia , Método Duplo-Cego , Quimioterapia Combinada , Tolerância a Medicamentos , Eletrocardiografia , Teste de Esforço , Feminino , Humanos , Locomoção , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Cintilografia , Distribuição Aleatória , Volume Sistólico/efeitos dos fármacosRESUMO
This study was performed (1) to assess the frequency of ventricular ectopic activity (ventricular bigeminy, couplets, or ventricular tachycardia) during spontaneous variant angina; (2) to assess the relation between ventricular ectopy and the severity and duration of ischemia; and (3) to evaluate the precise temporal relation between episodes of ischemia and ventricular ectopy. Fifteen ambulatory patients with variant angina (12 men, 3 women, aged 50 +/- 8 [mean +/- SD] years) had Holter monitoring for 24 hours/week for 10 months (total, 10,238 hours of monitoring), from which the following were measured during each episode of ST deviation (elevation or depression): duration of ST deviation (minutes), maximal ST deviation (millivolts), presence of ventricular ectopic activity, and timing of ventricular ectopy in relation to ST deviation. Of 645 episodes of ST deviation, 79 (12.2%) had associated ectopy, almost all of which occurred in three patients. The 79 episodes of ST deviation with ectopy lasted 4.6 +/- 3.3 minutes and averaged 0.16 +/- 0.12 mV, whereas the 566 episodes of ST deviation without ectopy lasted 4.7 +/- 6.1 minutes and averaged 0.17 +/- 0.11 mV (NS in comparison to the 79 episodes with ectopy). Of 489 episodes of ST elevation, 72 (14.7%) were accompanied by ventricular ectopy; of 156 episodes of ST depression, only seven (4.5%) had ectopy (chi 2 = 11.531, p less than 0.001). Of the 79 episodes of ventricular ectopy, almost all appeared during a period of increasing or maximal ST deviation, whereas only two appeared as ST deviation was resolving.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Angina Pectoris Variante/fisiopatologia , Arritmias Cardíacas/fisiopatologia , Adulto , Angina Pectoris Variante/complicações , Arritmias Cardíacas/complicações , Eletrocardiografia , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The present study was performed to assess the efficacy of concomitant calcium antagonist/isosorbide dinitrate therapy in patients with frequent episodes of variant angina and to compare such combination therapy with isosorbide dinitrate alone. We enrolled nine such patients (six men and three women, aged 47 +/- 9 [mean +/- standard deviation] years) in a long-term comparison of (1) oral isosorbide dinitrate (117 +/- 63 mg per day) alone, (2) verapamil (453 +/- 75 mg per day) + isosorbide dinitrate (given in the same dose as stated above), and (3) nifedipine (71 +/- 14 mg per day) + isosorbide dinitrate (also given in the same dose as stated), each administered for 2 months. During isosorbide dinitrate therapy, these nine patients averaged 23.7 +/- 37.3 chest pains per week, consumed 24.4 +/- 47.4 sublingual nitroglycerin tablets per week, and demonstrated 46.5 +/- 43.2 episodes per week of transient ST segment deviations on calibrated two-channel Holter monitoring. During therapy with verapamil/isosorbide dinitrate and nifedipine/isosorbide dinitrate, the frequency of angina and ST segment deviations was dramatically reduced (verapamil/isosorbide dinitrate, 3.9 +/- 3.6 chest pains per week and 3.5 +/- 2.6 ST segment deviations per week, p less than 0.05; nifedipine/isosorbide dinitrate, 3.1 +/- 4.0 chest pains per week and 5.5 +/- 6.6 ST segment deviations per week, p less than 0.05). In all respects, verapamil/isosorbide dinitrate and nifedipine/isosorbide dinitrate were similar to one another.(ABSTRACT TRUNCATED AT 250 WORDS)