Nifedipine gastrointestinal therapeutic system in stable angina pectoris. Results of a multicenter open-label crossover comparison with standard nifedipine.

To compare the clinical efficacy and dose equivalency of standard nifedipine versus a new gastrointestinal therapeutic system (GITS) formulation of nifedipine, 98 patients with chronic stable angina pectoris participated in a 14-week, multicenter, open-label, crossover trial. All patients were administered nifedipine capsules for one month prior to study entry and continued receiving other antianginal, non-calcium blocker medications. Ninety-one patients (93 percent), 80 men and 11 women, mean age 62 +/- 1 years, completed the trial, which included two weeks receiving standard nifedipine followed by 12 weeks receiving nifedipine GITS starting at a dosage equal to the 24-hour total dose of nifedipine capsules and titrated upward as necessary. However, throughout the trial, mean nifedipine dosage was similar on nifedipine GITS compared with standard nifedipine. Angina frequency was significantly less with nifedipine GITS at Weeks 6, 10, and 14 (0.8 episodes/week) compared with baseline with standard nifedipine (1.3 episodes/week, p less than 0.05). Likewise, nitroglycerin consumption was also less at Weeks 6, 10, and 14, but only significantly less at Week 6 (nifedipine 1.2/week versus nifedipine GITS at six weeks, 0.7/week; p less than 0.05). Resting hemodynamic parameters, including systolic and diastolic blood pressure and heart rate, were not significantly different with standard nifedipine versus nifedipine GITS during the 12-week study. Total incidences of side effects were similar for both treatments (standard nifedipine, 16; nifedipine GITS, 17). However, incidence of vasodilator side effects (flushing, dizziness, and light-headedness) was significantly less frequent with nifedipine GITS (standard nifedipine, 12; nifedipine GITS, six; p less than 0.05). Thus, results from this open-label, crossover trial suggest that nifedipine GITS dosing is similar to multidose standard nifedipine with equivalent 24-hour efficacy for nifedipine GITS.

Spasm of a saphenous vein bypass graft. A possible mechanism for occlusion of the venous graft.

The phenomenon of spasm in a venous graft was documented by angiographic study of the graft. This phenomenon has not been reported previously, and, therefore, its frequency of occurrence is unknown. Spasm of a venous graft may prove to play a significant role in the early development of myocardial infarction, closure of the graft, or recurrence of angina after initially successful surgery for aortocoronary bypass when venous grafts remain patent.

Dissimilar atrial rhythms diagnosed by echocardiography.

A 27-year-old woman with ectopic atrial rhythm and apparent atrioventricular dissociation was found to have A waves on the mitral echocardiogram that bore no relation to the P wave on the surface electrocardiogram. The ECG did not reflect the presence of dissimilar atrial rhythms, and their presence became apparent only during the echocardiographic studies. The mechanism of this phenomenon and its clinical implications are discussed.

Prevalence of clinical mitral-valve prolapse in 1169 young women.

Eleven hundred and sixty-nine young women were prospectively examined for the presence of mitral-valve prolapse as manifested by midsystolic non-ejection click or late systolic murmur (or both). Of the 1169 women 74 (6.3%) had physical findings consistent with mitral-valve prolapse. Sixty-eight of the 74 (92%) had midsystolic non-ejection click, and in 57 the click was accompanied by a late systolic murmur. In six (8%) only a late systolic murmur was heard. Echocardiography on all patients with clinical diagnosis of mitral-valve prolapse showed patterns of prolapse in 60 of 74 (81%). Fourteen (19%) had negative echocardiograms. We conclude that mitral-valve prolapse is clinically present in approximately 6.3% of otherwise healthy young women.