RESUMEN
This retrospective study examined the utilization of coronary stent placement versus PTCA in hemodialysis patients with obstructive coronary disease. Prior studies have demonstrated suboptimal results with PTCA owing primarily to high rates of restenosis. We identified 19 hemodialysis patients who received a percutaneous coronary intervention who were matched with individuals without renal failure undergoing same vessel revascularization. Our study found that 71% of hemodialysis patients receiving PTCA had a recurrent cardiac event defined by subsequent angina, myocardial infarction, or cardiac death. At follow-up, 30% of patients who received stent placement had recurrent cardiac events. Intracoronary stent placement is both safe and feasible and produces more favorable clinical outcomes in the management of coronary disease in hemodialysis patients.
Asunto(s)
Enfermedad de la Arteria Coronaria/cirugía , Diálisis Renal , Adulto , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/mortalidad , Estudios de Seguimiento , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/mortalidad , Fallo Renal Crónico/terapia , Persona de Mediana Edad , Estudios Retrospectivos , South Carolina/epidemiología , Stents , Análisis de Supervivencia , Tiempo , Resultado del TratamientoRESUMEN
We present an elderly patient who had syncope, with known coronary artery disease and a conduction abnormality. Because of a possible vasovagal reaction, the patient underwent a tilt table test prior to evaluation of ischemia or her LV function. During the tilt table test on isoproterenol, the patient developed ventricular fibrillation which was corrected immediately by cardioversion. Subsequently, the patient was found to have significant coronary artery disease which was treated with stenting and angioplasty. After treatment, there were no inducible arrhythmias on full dose isoproterenol. This case reports a significant complication that may occur when tilt table testing with isoproterenol and ischemia.
Asunto(s)
Isquemia Miocárdica/complicaciones , Pruebas de Mesa Inclinada/efectos adversos , Fibrilación Ventricular/etiología , Agonistas Adrenérgicos beta/efectos adversos , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón , Bloqueo de Rama/complicaciones , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/terapia , Cardioversión Eléctrica , Electrocardiografía , Femenino , Humanos , Isoproterenol/efectos adversos , Stents , Síncope Vasovagal/complicaciones , Fibrilación Ventricular/terapia , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/terapiaRESUMEN
Patients with internal cardioverter-defibrillators experience many issues after implantation. One issue is operating a motor vehicle. This issue has many ethical, legal and quality-of-life concerns that must be addressed by the patient, health care providers, and society. The legal and ethical issues surrounding patients with internal cardioverter-defibrillators will be explored using an ethically based theoretical framework.
Asunto(s)
Arritmias Cardíacas/terapia , Conducción de Automóvil , Desfibriladores Implantables , Ética , Calidad de Vida , Accidentes de Tránsito/estadística & datos numéricos , Conducción de Automóvil/legislación & jurisprudencia , Femenino , Libertad , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Ontario , Estados UnidosRESUMEN
BACKGROUND: Patients often depend on life-saving technology as a permanent part of their lives. Sometimes these devices become defective and are recalled. OBJECTIVES: To investigate how the urgent device recall of three models of the Automatic Implantable Cardioverter Defibrillator (AICD) affected confidence in the device and the psychosocial responses of patients and their family member caregivers. METHODS: All patients (N = 31) and caregivers (N = 21) affected by the recall at one heart center completed a survey instrument consisting of a series of visual analog scales designed to measure confidence before and after learning of the recall, fear, anger, depression, anxiety, helplessness, loss of control, uncertainty, and confusion associated with having a recalled AICD. Surveys were completed immediately after being told of the recall and 1 month later. RESULTS: Confidence of patients decreased significantly from a mean of 87% to 74% when comparing perceptions of before learning of the recall to those immediately after (t30 = 3.65, p < 0.0005). For caregivers, mean confidence dropped from 92% to 73% (t19 = 5.0, p < 0.0005). Confidence remained significantly lower 1 month later. Caregiver scores were consistently, although not significantly, higher (less favorable) on the measures of emotional response than patient scores. Caregivers of patients who had received shocks from the AICD and those of patients who had the device for more than a year were generally more affected. CONCLUSIONS: Patient and caregiver confidence in the AICD was significantly reduced. Further research is needed to investigate the trends in the data from caregivers.
Asunto(s)
Cuidadores/psicología , Desfibriladores Implantables , Falla de Equipo , Pacientes/psicología , Adulto , Anciano , Ansiedad , Seguridad de Equipos , Miedo , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To determine the driving behavior of patients following the placement of automatic implantable cardioverter defibrillators (AICDs). SUBJECTS AND DESIGN: Forty patients with AICDs (33 men, seven women; mean age, 62.7 years) responded to a questionnaire designed to ascertain driving behavior after hospital discharge. RESULTS: Despite medical advice never to drive again, 28 patients (70%) resumed driving, with the majority doing so by 8 months after AICD implantation. Of these, 11 (40%) identified themselves as the primary driver in their household. Fourteen (50%) drove daily. Two (7%) were driving and continued to drive during discharge of their AICDs. Twenty-five (91%) reported that they felt comfortable and safe while driving. CONCLUSION: A majority of patients with AICDs continue to drive after a proscription of this activity by health care workers.
Asunto(s)
Conducción de Automóvil/estadística & datos numéricos , Desfibriladores Implantables , Conducción de Automóvil/legislación & jurisprudencia , Conducción de Automóvil/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estados UnidosRESUMEN
Implantation of automatic internal cardiac defibrillators (AICD) for management of arrhythmias necessitates the induction of ventricular fibrillation (VF) to test the device adequately. The profound hypotension associated with induced arrhythmia and subsequent circulatory arrest may result in cerebral ischemia. To characterize cerebral ischemia, we used a five-lead Lifescan brain activity monitor to examine changes in cerebral activity in 10 patients having AICD placement. The duration of hypotension, as defined by a mean arterial pressure (MAP) < 50 mm Hg, was recorded, and the corresponding changes in brain activity were evaluated during 51 episodes of circulatory arrest. The number of episodes for each patient ranged from 2 to 14. The average duration of hypotension per episode was 26.2 seconds, with a range of 8 to 67 seconds. Brain activity changes characteristic of cerebral ischemia occurred in 46 of the 51 events (90%). Cerebral ischemia did not occur when the duration of hypotension was less than 16 seconds (5 episodes). The duration of cerebral ischemia ranged from 50 to 279 seconds (average 84.9 seconds) and did not correlate with the duration of hypotension or the order of the episodes in the testing sequence. These findings suggest that reevaluation of standard monitoring practice for AICD implantation may be warranted.
Asunto(s)
Desfibriladores Implantables , Electroencefalografía , Monitoreo Intraoperatorio , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/etiología , Femenino , Humanos , Hipotensión/etiología , Complicaciones Intraoperatorias/diagnóstico , Masculino , Persona de Mediana Edad , Fibrilación Ventricular/etiología , Fibrilación Ventricular/fisiopatologíaRESUMEN
We have developed a solid-phase enzyme immunoassay for anti-oxidized low-density lipoprotein antibodies. Most sera showed some degree of non-specific binding to plates coated with oxidized low-density lipoprotein and the autoantibodies to oxidized low-density lipoprotein often appeared to have a relatively low affinity. To differentiate between specific and non-specific binding each sample was tested untreated and after absorption with oxidized low-density lipoprotein. The optical densities obtained with dilutions of the absorbed sample were considered to reflect non-specific binding and were subtracted from values obtained with identical dilutions of the unabsorbed sample, to yield corrected values from which the concentrations of anti-oxidized low-density lipoprotein antibody were calculated. Similar absorptions with native low-density lipoprotein and oxidized human serum albumin failed to induce a significant reduction in binding to immobilized oxidized low-density lipoprotein proving that the antibodies measured by this assay are primarily specific for oxidized low-density lipoprotein. We studied sera from two groups of individuals: (1) 33 subjects submitted to coronary angiography and split into two subgroups depending on the degree of coronary stenosis and (2) 64 healthy individuals also split into two subgroups according to lipid levels. Anti-oxidized low-density lipoprotein antibodies were detected both in patients and healthy individuals. Higher levels were detected in patients with moderate coronary disease and hyperlipemic healthy individuals, but the differences between patients and healthy volunteers or between their respective subgroups did not reach statistical significance. Our results suggest that autoantibodies to oxidized low-density lipoprotein are relatively frequent in both symptomatic and asymptomatic individuals.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Autoanticuerpos/sangre , Enfermedad Coronaria/inmunología , Lipoproteínas LDL/inmunología , Humanos , Técnicas para Inmunoenzimas , Oxidación-Reducción , Valores de ReferenciaRESUMEN
Previous studies have shown that single-chamber sensor-driven pacing improves exercise tolerance for patients with chronotropic incompetence. However, long-term single-chamber pacing has a number of inherent problems that limit its usefulness. Although sensor-driven dual-chamber pacing largely obviates the problems inherent with single-chamber sensor-driven pacing, the physiologic benefit of dual-chamber sensor-driven pacing has not yet been demonstrated. Accordingly, the purpose of this study was to compare exercise-induced cardiac output for patients with chronotropic incompetence, after programming their pacemakers to either a simulated sensor-driven single or simulated dual-chamber mode. Cardiac output was measured noninvasively at rest and peak exercise using standard Doppler-derived measurements, obtained in a blinded fashion. At rest the Doppler-derived resting VVI and DDD cardiac outputs were 4.49 +/- 0.3 L/min and 4.68 +/- 0.3 L/min, respectively. At peak exercise, the DDD cardiac output was 5.07 +/- 0.5 L/min, whereas the simulated activity VVI and DDD cardiac outputs were 6.33 +/- 0.6 L/min and 7.41 +/- 0.70 L/min, respectively. Analysis of variance showed that there was an overall significant difference in cardiac output from rest to peak exercise (p less than 0.001). However, only the simulated activity DDD cardiac output was significantly different from its respective control value (p less than 0.05). Thus this study shows for the first time that the addition of rate responsiveness to dual-chamber pacing results in a significant improvement in cardiac output for patients with chronotropic incompetence.
Asunto(s)
Gasto Cardíaco , Estimulación Cardíaca Artificial/métodos , Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Marcapaso Artificial , Anciano , Diseño de Equipo , Bloqueo Cardíaco/terapia , Humanos , Masculino , Persona de Mediana Edad , Síndrome del Seno Enfermo/terapiaRESUMEN
Bacterial endocarditis secondary to endoscopic procedures has been convincingly documented in only four cases. We describe a case of prosthetic valve endocarditis due to Cardiobacterium hominis that developed after upper gastrointestinal endoscopy. Because of this, we recommend subacute bacterial endocarditis prophylaxis in patients who have a prior history of endocarditis or valve replacement.
Asunto(s)
Endocarditis Bacteriana Subaguda/etiología , Gastroscopía/efectos adversos , Prótesis Valvulares Cardíacas/efectos adversos , Válvula Aórtica , Ceftriaxona/uso terapéutico , Ecocardiografía , Endocarditis Bacteriana Subaguda/tratamiento farmacológico , Endocarditis Bacteriana Subaguda/fisiopatología , Bacterias Gramnegativas/aislamiento & purificación , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The incidence and severity of catheter-induced tricuspid regurgitation has not been studied extensively. Given the frequency with which right heart catheters are employed to measure cardiac output, it is important to know whether the severity of catheter-induced tricuspid regurgitation is sufficient to invalidate the measurement of thermodilution cardiac output. Accordingly, the purpose of the present prospective study was to determine the incidence and severity of catheter-induced tricuspid regurgitation in 25 men (mean age, 58.1 +/- 1.4 years) using Doppler ultrasound. The tricuspid valve was interrogated from two orthogonal views using pulsed-wave and color flow Doppler, either in the presence or absence of a 7-French catheter across the tricuspid valve. The severity of catheter-induced tricuspid regurgitation was graded semiquantitatively using a validated scoring system. Pulsed-wave Doppler studies showed that the incidence of catheter-induced tricuspid regurgitation was 48 percent, and that the average tricuspid regurgitation score increased from 0.41 +/- 0.16 to 0.61 +/- 0.17 (p less than 0.01). Color flow Doppler studies showed similar findings. Further, the incidence of catheter-induced tricuspid regurgitation was not related to the patient's underlying hemodynamic status or right ventricular geometry. In conclusion, this study shows for the first time that the quantitative extent of catheter-induced tricuspid regurgitation is small, and is therefore unlikely to be important clinically, particularly with regard to the assessment of thermodilution cardiac output.
Asunto(s)
Cateterismo Cardíaco/efectos adversos , Insuficiencia de la Válvula Tricúspide/etiología , Cateterismo Cardíaco/instrumentación , Ecocardiografía , Ecocardiografía Doppler , Hemodinámica , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Insuficiencia de la Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/fisiopatologíaRESUMEN
The Activitrax rate responsive pacemaker system has enjoyed wide popularity but minor engineering eccentricities have occurred and have been reported. We report another unusual feature seen in Activitrax models 8400, 8402, and 8403. This feature consists of continuing in a temporary mode while a different permanent mode was programmed. These eccentricities of the programming features are not very commonly seen, however, they can be somewhat perplexing to the physician following the patient. These unusual features are no longer present in the newer models being manufactured.
Asunto(s)
Marcapaso Artificial , Ingeniería Biomédica , Electrocardiografía , Diseño de Equipo , Frecuencia Cardíaca , Humanos , Magnetismo , Masculino , Persona de Mediana EdadRESUMEN
Sensor-driven pacemakers have clinically improved symptomatology over ventricular pacemakers. Adding rate responsiveness to DDD pacing would theoretically benefit patients with an inability to increase their atrial rate. We evaluated 20 patients who had long-term implanted DDD pacemakers as to the utility of an added effect of rate responsiveness. The pacemakers had been implanted for an average of 34 months. This patient group included 15 patients with atrioventricular (AV) block and five patients with sick sinus syndrome. All patients were exercised on the treadmill until they were fatigued and were monitored to determine their intrinsic heart rate response. A sensor-driven pacemaker was strapped to the patients and was connected to an ECG to measure its rate response. It was set to activity threshold of medium, with a rate response of 7. The 20 patients exercised for an average of 5.9 minutes, with a range of 1.7 to 10 minutes. The maximum intrinsic atrial response averaged 110 beats/min, ranging from 60 to 150 beats/min. The maximum achieved activity rate averaged 99 beats/min, ranging from 60 to 118 beats/min. In 7 of the 20 of patients (35%), the activity pacemaker reached a higher rate than the patient's intrinsic rate. Six had AV block and one had sick sinus syndrome. In these seven patients the peak activity rate response averaged 102 beats/min and their intrinsic activity averaged to 78 beats/min. There was an increase in rate by the addition of rate responsiveness in 35% of our DDD patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Estimulación Cardíaca Artificial/métodos , Marcapaso Artificial , Adulto , Anciano , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/terapia , Diseño de Equipo , Prueba de Esfuerzo , Femenino , Corazón/fisiopatología , Atrios Cardíacos , Frecuencia Cardíaca , Ventrículos Cardíacos , Humanos , Masculino , Persona de Mediana Edad , Descanso , Factores de TiempoRESUMEN
Congenital left ventricular pressure overload is associated with "excessive" hypertrophy that leads to subnormal afterload (wall stress), permitting enhanced ventricular ejection performance. Whether congenital right ventricular pressure overload is associated with a similar phenomenon is uncertain. It is also unknown whether supranormal ejection performance affects only the overloaded ventricle or is a general process affecting both ventricles. Conflicting data exist about whether the hypertrophic process associated with pressure overload is induced primarily by local loading conditions or by neuroendocrine influences. If the former postulate is true, the hypertrophic response should be confined to the overloaded ventricle; if the latter is true, one might predict that both ventricles would be affected by a less specific response to circulating catecholamines. To help resolve these issues, both right and left ventricular performance was examined in seven patients with isolated congenital pulmonary stenosis (average pulmonary pressure gradient 78 +/- 13 mm Hg), six patients with isolated congenital aortic stenosis (average gradient 80 +/- 10 mm Hg) and six normal subjects. Right ventricular ejection fraction was increased in patients with pulmonary stenosis (61 +/- 2%) compared with the value in normal subjects (53 +/- 2%, p less than 0.01) and in patients with aortic stenosis (50 +/- 3%, p = 0.007). Left ventricular ejection fraction was increased in patients with congenital aortic stenosis (84 +/- 4%) compared with the value in normal subjects (70 +/- 4%, p less than 0.01) and in patients with congenital pulmonary stenosis (65 +/- 2%, p less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Estenosis de la Válvula Aórtica/congénito , Estenosis de la Válvula Pulmonar/congénito , Volumen Sistólico , Estenosis de la Válvula Aórtica/fisiopatología , Cardiomegalia/etiología , Cardiomegalia/fisiopatología , Niño , Humanos , Contracción Miocárdica , Estenosis de la Válvula Pulmonar/fisiopatologíaRESUMEN
The time of occurrence of cardiac pacemaker problems after implantation was identified to assess the adequacy of published federal guidelines for clinic and transtelephonic follow-up. One hundred eighty-nine pacemaker patients' charts were examined retrospectively to identify pacemaker problems: inadequate sensing, non-capture, battery failure, myoinhibition, muscle stimulation, and inadequate threshold safety margin. Twenty-nine patients (15%) were identified as having pacemaker problems. A total of 41 problems were identified, of which 28 (68%) were corrected by reprogramming. Sixty-one percent of the problems were found during a clinic visit. Problems occurred more frequently during the first year in dual-chamber devices (62%) vs single-chamber devices (35%). During years 1 to 4, when few problems are expected, 30% of all problems of single-chamber devices occurred and 39% of all problems of dual-chamber devices occurred. This is a period of time that Medicare guidelines allow for one clinic visit per year for single- and two visits per year for dual-chamber devices. These data suggest: (1) Many pacemaker problems will be missed with transtelephonic follow-up alone. (2) The majority of problems involving dual-chamber devices occurred in the first year. (3) For both dual- and single-chamber devices, an unexpected significant percentage of problems occurred in 1 to 4 years. (4) Medicare guidelines may be inadequate for follow-up during this time period.
Asunto(s)
Medicare , Marcapaso Artificial/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Diseño de Equipo , Falla de Equipo , Estudios de Seguimiento , Bloqueo Cardíaco/terapia , Humanos , Persona de Mediana Edad , Monitoreo Fisiológico , Visita a Consultorio Médico , Marcapaso Artificial/normas , Síndrome del Seno Enfermo/terapia , South Carolina , Teléfono , Factores de TiempoRESUMEN
To assess and compare the rates of lead dislodgment and pocket infection in patients having procedures performed in the operating room versus those performed in the cardiac catheterization laboratory, we reviewed the records of 85 adult patients who underwent 88 procedures, all performed by one surgical team and having complete follow-ups at our institution from October 8, 1979, through November 7, 1986. Forty-five patients underwent 46 procedures in the operating room, and 40 patients underwent 42 procedures in the cardiac catheterization laboratory. There was one instance of ventricular lead dislodgment noted among the 48 leads implanted in the operating room and one instance of ventricular lead dislodgment among the 58 leads implanted in the cardiac catheterization laboratory. No instances of atrial lead dislodgment were noted. No instances of pocket infection were noted among the 46 procedures performed in the operating room or in the 42 procedures performed in the cardiac catheterization laboratory. We conclude that pacemaker implantation can be performed with equivalent safety and effectiveness in the cardiac catheterization laboratory and in the operating room.
Asunto(s)
Cateterismo Cardíaco , Electrodos Implantados , Quirófanos , Marcapaso Artificial , Infección de la Herida Quirúrgica/epidemiología , Adulto , Estudios de Seguimiento , HumanosRESUMEN
The appropriateness of serum digoxin concentration (SDC) orders was evaluated with respect to indication for use, sampling time, and action taken by physicians when the reported SDC was out of the normal therapeutic range; the effect of the two data-collection methods used (retrospective and concurrent audits) on the results was studied. Criteria for the appropriate use of SDCs were approved by the medical staff through the pharmacy and therapeutics committee. Patients on adult medicine services were entered into the study as daily SDC determinations were reported by the clinical laboratory. Most of the SDCs were evaluated using approved criteria by primary pharmacist clinicians who were concurrently monitoring drug therapy and participating with the treatment team. A retrospective audit of the same patients was conducted, using only chart review. A total of 134 SDCs involving 78 patients were evaluated. Concurrent-audit results indicated that 18.7% of the SDCs were ordered without an appropriate indication, 16.4% were sampled incorrectly with respect to proper timing, and 8.2% did not result in dosage adjustments when indicated. With respect to appropriate sampling time and overall use of SDCs, significantly more SDCs met the standards under concurrent audit than under retrospective audit. The retrospective chart review method of auditing may not detect as much pertinent information as is desirable.
Asunto(s)
Recolección de Datos/métodos , Digoxina/sangre , Auditoría Médica/métodos , Monitoreo Fisiológico , Revisión Concurrente , Digoxina/administración & dosificación , Hospitales con más de 500 Camas , Humanos , Estudios Retrospectivos , South CarolinaRESUMEN
The purpose of this study was to determine if serum digoxin concentration data using three different automated immunoassay methods would produce similar pharmacokinetic values in normal volunteer subjects. Area under the curve (AUC), steady-state volume of distribution/bioavailability ratio (Vd/F), terminal elimination rate constant (beta), clearance/bioavailability ratio (CL/F), maximum digoxin concentration (Cmax), minimum digoxin concentration (Cmin), and time of peak (Tp) were evaluated. Ten healthy volunteers received digoxin capsules 0.2 mg daily for 10 days. On day 10, 16 serial blood samples were collected over a 24-h dosing interval and analyzed by radioimmunoassay (RIA) (Concept 4, Micromedic Systems), fluorescence polarization immunoassay (FPIA) (TDx, Abbott Laboratories), and affinity column-mediated immunoassay (ACMIA), (aca, duPont Instruments). When comparing RIA and FPIA, the mean of the percent differences for AUC, Vd/F, beta, and CL/F were 9, 4, 10, and 6%, respectively. The mean of the percent differences were 2, 3, 44, and 6%, respectively, when comparing RIA and ACMIA. However, none of these differences were statistically significant. Although a trend toward higher Cmax values by RIA was noted, there was no statistical difference in Cmax, Cmin, and Tp. Orthogonal regression of all serum digoxin concentrations showed that FPIA = 0.76 RIA + 0.19, r = 0.967 (p less than 0.001); and ACMIA = 0.92 RIA + 0.04, r = 0.943 (p less than 0.001). At serum digoxin concentrations less than 1 ng/ml, FPIA overestimated RIA results (p less than 0.005), while ACMIA was approximately equal to the RIA results.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Digoxina/farmacocinética , Saponinas , Proteínas Sanguíneas/análisis , Cardenólidos , Cromatografía de Afinidad , Polarización de Fluorescencia , Humanos , Masculino , Radioinmunoensayo , Análisis de RegresiónRESUMEN
To determine if a sustained-release form of the calcium entry blocker diltiazem would be a satisfactory substitute for the combination of beta-adrenergic blocking agent and thiazide diuretic in the treatment of systemic hypertension and angina pectoris, 38 patients were studied in a 4-center trial. Blood pressure and heart rate were measured in the supine position, immediately after and 5 minutes after standing. Modified Bruce protocol treadmill tests were performed to determine the time to onset of 1 mm ST-segment depression, time to onset of chest pain and time to termination of exercise. Diltiazem monotherapy resulted in equivalent blood pressure control in 28 of 38 patients (74%). In the remaining patients, blood pressure control was achieved with resumption of the diuretic. Blood pressure with beta blocker plus diuretic compared with diltiazem were, in the supine position 137 +/- 22/82 +/- 7 (+/- 1 standard deviation) versus 139 +/- 22/82 +/- 8 mm Hg, immediately after standing 131 +/- 20/84 +/- 9 versus 133 +/- 21/82 +/- 10 mm Hg and after standing for 5 minutes 134 +/- 19/85 +/- 8 versus 137 +/- 18/85 +/- 9 mm Hg (difference not significant for each). The heart rate with diltiazem was higher supine (67 +/- 11 versus 60 +/- 11 beats/min), standing (73 +/- 13 versus 64 +/- 14 beats/min) and 5 minutes after standing (73 +/- 14 versus 63 +/- 14 beats/min, p less than 0.01 for each).(ABSTRACT TRUNCATED AT 250 WORDS)