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Biomedical subjects

I H Lamb

Publications and source records attributed to I H Lamb.

15 recordsLinked to original sources
PubMed1985

Diltiazem and propranolol, alone and in combination, on exercise performance and left ventricular function in patients with stable effort angina: a double-blind, randomized, and placebo-controlled study.

Diltiazem and propranolol alone and in combination as antianginal agents were compared with placebo in 12 patients with stable exertional angina at Stanford University Medical Center. The patients performed symptom-limited, multi-stage upright bicycle ergometric exercise while undergoing radionuclide angiographic studies every two weeks while being treated with 90 mg of diltiazem four times daily, 60 mg of propranolol four times daily, a combination of 90 mg of diltiazem and 60 mg of propranolol four times daily, and placebo. Diltiazem, propranolol and a combination all significantly increased exercise duration compared to placebo (526 +/- 149, 525 +/- 115, and 549 +/- 129 vs 430 +/- 132 sec.). Although rate pressure product and heart rate decreased with diltiazem therapy at submaximal workloads, these values were unchanged at peak exercise in contrast to propranolol or the combination of propranolol or diltiazem. Diltiazem decreased the sub-maximal and maximal degree of exercise-induced ST segment depression by over 50% compared to placebo (P less than 0.01 vs placebo). Diltiazem resulted in a higher exercise left ventricular ejection fraction compared to placebo, propranolol or the combination of diltiazem or propranolol (all less than P less than 0.05). Sinus bradycardia or orthostatic hypertension occurred in four patients on the high-dose combination therapy and required dose reduction. We concluded that high-dose diltiazem, appeared to be even more effective than moderate-dose propranolol or the combination of diltiazem and propranolol in improving exercise tolerance, electrocardiographic evidence of myocardial ischaemia and left ventricular function in patients with stable effort angina due to occlusive coronary artery disease.

Aged↗
PubMed1983

Prevention of cardiovascular events in variant angina by long-term diltiazem therapy.

In 43 patients with variant angina, the cardiovascular event rate during diltiazem therapy was compared with that in an equal time period before initiation of therapy. Cardiovascular events, that is, myocardial infarction, sudden death and hospitalization for prolonged angina, were decreased significantly (p less than 0.01) during the initial 6 months and mean 19.6 months of therapy. Based on the binomial principle, there were 22 events during the mean 19.6 months before therapy and 2 events during the equal time period on therapy. No patient died during follow-up. The frequency of angina was decreased by 94%. Diltiazem was well tolerated by all patients and no patient had to discontinue therapy because of adverse effects. It is concluded that long-term diltiazem therapy reduces cardiovascular events in patients with variant angina.

Adult↗
PubMed1983

Long-term efficacy of diltiazem for control of symptoms of coronary artery spasm.

In order to evaluate long-term efficacy of a new calcium antagonist, diltiazem, for therapy of coronary artery spasm, 16 patients with clinical variant angina due to documented coronary artery spasm participated in a 44-week prospective, randomized, double-blind cross-over trial of 240 mg of diltiazem vs. placebo. The study involved eleven 28-day cycles of which one of the first five cycles (phase 1) and one of the last six cycles (phase 2) were placebo, with the remainder being active medication. Response was assessed with the dairy technique, measuring frequency of angina and side effects. When diltiazem was compared with the placebo period during phase 1, there was a 73% decrease in frequency of angina from 1.1 to 0.3 episodes per day (P less than 0.01). When diltiazem was compared with the placebo during phase 2, there was an 80% decrease in frequency of angina from 0.5 to 0.1 episodes per day (P less than 0.05). When phase 1 placebo cycle was compared with phase 2 placebo cycle, there was a 55% decrease in frequency of angina which approached statistical significance (P less than 0.10). This marked disease attenuation demonstrated during the 44-week study reflects the variability of symptoms of variant angina and possibly reflects a carry-over therapeutic effect of the calcium entry blocker. Adverse side effects were absent in our small group of patients. Diltiazem is effective for the long-term control of symptoms of active coronary artery spasm.

Adult↗
PubMed1982

Diltiazem for long-term therapy of coronary arterial spasm.

The first 36 patients with coronary arterial spasm treated with diltiazem and followed up at the Stanford University Coronary Artery Spasm Clinic for 6 months or longer are described. There were 13 men and 23 women with a mean age of 50.2 years; the mean duration of angina was 36.1 months. All patients had angina at rest with a good or fail response to sublingual nitroglycerin. During a mean of 17.5 months of diltiazem therapy, the frequency of angina was reduced from a mean of 21.5 to 1.3 attacks/week. This 94 percent reduction in pain frequency occurred when either 240 or 360 mg of diltiazem was administered daily. Sixteen patients required the addition of isosorbide dinitrate to achieve a painfree state. Pain breakthrough occurred a mean of 1.7 times during the 17.5 month follow-up period but tended to be of short duration. Six patients had trace to 1+ pedal edema and no other adverse effects occurred. It is concluded that diltiazem is highly effective and well tolerated for the long-term prophylaxis and treatment of angina in patients with coronary spasm.

Adult↗
PubMed1982

Randomized double-blind comparison of nifedipine and isosorbide dinitrate therapy in variant angina pectoris due to coronary artery spasm.

Twelve patients were entered prospectively into a randomized double-blind study comparing the efficacy of nifedipine and isosorbide dinitrate (ISDN) in the treatment of variant angina pectoris due to coronary artery spasm. Using the diary technique, both anginal episodes and nitroglycerin tablets consumed were recorded during the pretrial, no drug period, and both active drug phases. During the baseline pretrial period, an average of 1.1 anginal episodes/day occurred with reduction to 0.28/day during nifedipine treatment and 0.39/day during ISDN treatment. Headache was the major side effect during ISDN treatment, occurring in 9 of 11 (81%) patients; and nonheart failure related pedal edema during nifedipine treatment, occurring in 4 of 12 (33%) patients. Intolerable side effects necessitating cessation of treatment occurred in two patients during nifedipine treatment and in three patients during ISDN treatment. Patients preferred nifedipine over ISDN because of increased efficacy and fewer uncomfortable side effects. We conclude that both nifedipine and ISDN are effective therapy for coronary spasm, but that nifedipine was more effective and was preferred by the majority of patients.

Adult↗
PubMed1981

Application and safety of outpatient ergonovine testing in accurately detecting coronary spasm in patients with possible variant angina.

We analyzed the results of 61 consecutive outpatient ergonovine provocation tests to determine the safety and efficacy of such outpatient testing for detecting coronary artery spasm (CAS). Criteria for outpatient testing included: clinical history suggestive of variant angina, noncritical coronary artery disease documented by coronary arteriography, normal exercise treadmill test, no symptomatic arrhythmias, and no history of recent myocardial infarction. All antianginal medications were tapered and stopped. Ergonovine maleate was given as a bolus at 3-minute intervals in consecutive doses of 0.05, 0.10, and 0.25 mg. A positive test was defined as chest pain accompanied by greater than 0.1 mV ST segment elevation of 12-lead ECG. If pain and ST-segment elevation occurred, intravenous and sublingual nitroglycerin were immediately administered for relief of myocardial ischemia. Of the 61 patients studied, 10 had positive tests; there were no complications. Follow-up the 51 patients with negative studies has not revealed cardiac etiology for their chest pain. We conclude that outpatient ergonovine testing is a safe and accurate diagnostic test for identifying CAS in a highly selected population of patients with possible variant angina when performed under carefully controlled conditions.

Adult↗
PubMed1981

Long-term transtelephonic electrocardiographic monitoring in the detection and evaluation of variant angina.

To facilitate the outpatient diagnosis of variant angina by documenting transient ST segment evaluation during chest pain, we studied the feasibility of transtelephonic ECG monitoring during angina episodes. Eight patients with known coronary artery spasm underwent simultaneous continuous ambulatory and transtelephonic ECG monitoring during a 24-hour period. Five patients (62%) had transient diagnostic ST segment shifts on both continuous ambulatory and transtelephonic monitoring. Another eight patients with coronary spasm underwent 24-hour continuous ambulatory monitoring and separate 14-day period of transtelephonic monitoring. The addition of this longer monitoring period provided diagnostic ST segment shifts in three patients. We conclude that transtelephonic monitoring in patients with suspected coronary artery spasm can provide important additional diagnostic information to continuous ambulatory monitoring, particularly in the patient with infrequent or predictable chest pain.

Adult↗
PubMed1980

Efficacy of diltiazem for control of symptoms of coronary arterial spasm.

To evaluate the efficacy of the calcium antagonist diltiazem for therapy of active coronary arterial spasm, 13 patients with clinical variant angina attributed to documented coronary arterial spasm completed a prospective randomized double-blind crossover trial of diltiazem (120 and 240 mg/day) versus placebo. Response was assessed with the diary technique measuring frequency of angina, consumption of nitroglycerin and percent of pain-free days. When 120 mg of diltiazem/day was compared with the paired placebo period there was a significant increase in percent of pain-free days (from 43 to 71 percent [p = 0.03]), but no significant decrease in frequency of angina (p = 0.06) or consumption of nitroglycerin (p = 0.32). When 240 mg of diltiazem/day was compared with the paired placebo period there was a significant increase in percent of pain-free days (from 50 to 79 percent [p = 0.03]) and a significant decrease in both frequency of angina (from 1.6 to 0.4 episodes/day [p = 0.03]) and consumption of nitroglycerin (from 1.3 to 0.4/day [p = 0.01]). Diltiazem was found to be a highly effective drug for control of symptoms of active coronary arterial spasm, without side effects and with excellent patient tolerance.

Aged↗
PubMed1980

Do patients in whom myocardial infarction has been ruled out have a better prognosis after hospitalization than those surviving infarction?

To determine the prognosis after hospitalization of patients hospitalized with acute chest pain in a coronary-care unit, we undertook a prospective study of 211 consecutive admissions to the Stanford Coronary Care Unit. On the basis of predetermined criteria, 16 patients were found to have noncardiac chest pain, and myocardial infarction was ruled out in 89, one of whom died in the hospital. Infarction was documented in 84 others, six of whom died in the hospital. Prospective follow-up after hospitalization was carried out in the 88 patients in whom infarction was ruled out and in the 78 patients who survived infarction. The rate of myocardial infarction or death was 8.0 per cent at six months and 21.6 per cent at a mean of 27.8 months of follow-up for patients who had infarction ruled out, as compared with 7.7 per cent at six months and 21.8 per cent at a mean of 27.8 months of follow-up for those who had a documented infarction during the initial hospitalization. Cardiomegaly, congestive heart failure, and angina after discharge from the hospital tended to increase the risk of morbidity and mortality in both groups. The patient hospitalized with acute ischemic chest pain without evolution of a myocardial infarction has a six to 24-month prognosis similar to that of the patient hospitalized with an acute infarction, and therefore requires similar diagnostic and therapeutic assessment.

Angina Pectoris↗
PubMed1979

Prodromal characteristics as indicators of cardiac events in patients hospitalized for chest pain.

In an effort to determine the usefulness of prodromata for predicting a myocardial infarction, a prospective analysis was made of 211 consecutive patients with chest pain who were admitted to the Stanford University Medical Center Coronary Care Unit. In their subsequent course, 91 patients had a myocardial infarction, 102 had a myocardial infarction ruled-out, and 18 had a noncardiac etiology for their chest pain. Prodromal chest pain in the previous six months had occurred in 65% of patients and unstable angina in 61%. Infarction versus noninfarction patient groups could not be identified on the basis of prodromal ill health, chest pain, unstable angina, typical versus atypical nature of the chest pain, or activity at the onset of pain. Complaints of preceding fatigue and increased perceived stress were common in both groups. Activity at the onset of the admission chest pain was strenuous in 15% of the infarction patients and 12% of the noninfarction patients. We conclude that prodromal symptoms are common in both infarction and noninfarction patients. Although chest pain probably remains the single most frequent identifier of a new cardiac event, it is common in noninfarction patients and cannot be used alone to predict infarction or death.

Adult↗
PubMed1977

Patients admitted to the coronary care unit for chest pain: high risk subgroup for subsequent cardiovascular death.

Approximately 300 persons a year who are admitted to the Stanford University Hospital coronary care unit because of prolong ischemic chest pain and transient S-T changes do not manifest evidence of a myocardial infarction during their hospital stay. In a retrospective study carried out in 170 such patients, follow-up data obtained during a mean of 17.9 months revealed rates of mortality from cardiovascular causes of 4.2 percent for 1 month, 10.1 percent for 1 year and 19.7 percent for the entire follow-up period. Ten (40 percent) of the 23 deaths that occurred were sudden and 13 were due to acute myocardial infarction or its complications. Another 21 patients had a nonfatal myocardial infarction during this follow-up period. The data confirm the impression that patients with suspected myocardial infarction who do not have an infarction in the coronary care unit are at high risk for cardiovascular deaths after hospital discharge. Efforts are under way to define further a high risk subgroup on the basis of clinical indications before discharge.

Adult↗