Angioscopy of culprit coronary lesions in unstable angina pectoris and correlation of clinical presentation with plaque morphology.

This study demonstrates that plaque disruption and thrombus are absent in a considerable number of patients with unstable angina and that culprit lesion morphologies as assessed by angioscopy may differ among the various clinical subsets of patients. Although plaque disruption and thrombus undoubtedly play an important role in the pathogenesis of unstable angina, alternative mechanisms may be responsible for ischemia in some patients.

Angioscopic assessment of coronary lesions underlying thrombus.

This study examines the characteristics of coronary lesions in which thrombus is found as assessed by angioscopy before percutaneous transluminal coronary angioplasty in patients with various coronary syndromes. Our findings demonstrate that the plaque underlying intracoronary thrombus is usually yellow and/or disrupted, and support in vitro observations that lipid-rich plaques are highly thrombogenic and that disruption of these plaques is associated with in situ thrombosis.

Pulsed Doppler evaluation of atrial mechanical function after electrical cardioversion of atrial fibrillation.

Full recovery of atrial mechanical activity may not occur immediately after successful electrical cardioversion of atrial fibrillation to sinus rhythm. To examine the time course of recovery of left atrial mechanical function, serial two-dimensional, M-mode and transmitral pulsed Doppler echocardiographic studies were performed in 21 patients after elective direct current cardioversion of atrial fibrillation of 3 weeks' to 24 months' duration (mean 5 months). Over 3 months of follow-up, there were significant increases in both peak A wave velocity (p less than 0.005) and percent atrial contribution to total left ventricular filling (p less than 0.005). Compared with values in a normal control population, peak A wave velocity and percent atrial contribution to total left ventricular filling did not return to normal until 3 weeks after cardioversion in patients who remained in sinus rhythm. Left atrial dimension also decreased over the follow-up period (p less than 0.05) in patients with persistent sinus rhythm. These results may have important implications in guiding the appropriate duration of anticoagulant therapy after cardioversion, and in clinically assessing the hemodynamic benefit of restoring sinus rhythm in an individual patient.

Use of percutaneous transluminal coronary angioplasty and bypass surgery despite improved medical therapy for unstable angina pectoris.

To evaluate current strategies for the management of unstable angina, 104 consecutive patients admitted to the coronary care unit with unstable angina during a 6-month period were followed prospectively. Although 58 patients had symptomatic relief with the initiation of intensive medical therapy, 46 (44%) continued to have episodes of angina despite maximal tolerated triple-drug antianginal therapy as well as aspirin or heparin, or both. In-hospital mortality for the 104 patients was 4%. The incidence of myocardial infarction was 8%, and differed (p less than 0.01) for the medically responsive group (3%) vs the medically refractory group (13%). Based on clinical status and coronary anatomy, patients were referred for either bypass surgery (46%), coronary angioplasty (41%) or continued medical therapy (13%). Choice of therapy varied according to the extent of coronary disease, with coronary angioplasty attempted in 72% of patients with 1-vessel disease, 44% of patients with 2-vessel disease and 7% of patients with 3-vessel disease. Angioplasty was performed with an initial success rate of 88%, and compared favorably with bypass surgery in terms of in-hospital mortality (0 vs 11%), late mortality (2.8 vs 7.7%), freedom from angina (62 vs 69%) and subsequent employment (44 vs 27%) at 18 months follow-up. The favorable results of angioplasty in this prospective observational study suggest that additional randomized trials should be conducted in this important patient group.

Doppler echocardiography in cardiac tamponade: exaggerated respiratory variation in transvalvular blood flow velocity integrals.

Pulsed Doppler echocardiography has been used previously to demonstrate marked changes in transvalvular blood flow velocities during cardiac tamponade in laboratory animals and a small number of patients. To further assess the respiratory changes in transvalvular blood flow during tamponade, pulsed Doppler tracings of flow velocity profiles across all four cardiac valves were recorded during inspiration and expiration in 13 patients during cardiac tamponade, in 6 of the 13 patients after relief of tamponade by pericardiocentesis and in 8 normal control subjects. Flow velocity integrals were calculated for each valve during inspiration and expiration. In the setting of cardiac tamponade, inspiration caused an 85 +/- 46% increase in the flow velocity integral across the pulmonary valve, an 81 +/- 34% increase across the tricuspid valve, a 33 +/- 13% decrease across the aortic valve and a 35 +/- 8% decrease across the mitral valve. These phasic respiratory changes were markedly reduced after relief of tamponade (p less than 0.05 compared with tamponade) and were observed to only a minimal extent in the normal individuals (p less than 0.01 compared with tamponade). The exaggerated respiratory variations in transvalvular flow velocity integrals suggest that Doppler evaluation may be a valuable tool in the diagnosis of cardiac tamponade. Transmitral Doppler indexes of left ventricular filling during cardiac tamponade revealed that inspiration caused a shift to increased filling during late diastole, with a greater contribution of atrial systole to total left ventricular filling. These Doppler indexes did not vary significantly with respiration in the group studied after relief of tamponade or in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)