David E. Leeman

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)

Plaque disruption and thrombus in Ambrose’s angiographic coronary lesion types

Lesion eccentricity with irregularities on coronary angiography is associated with ruptured plaques and thrombus based on postmortem and clinical angiographic studies. However, the predictive value of such angiographic markers of plaque disruption and thrombus remains to be determined in vivo. The purpose of this study was to establish whether Ambroses angiographic coronary lesion types and other angiographic criteria predict the presence of disrupted plaques and thrombus using intracoronary angioscopy. Angioscopy was performed before angioplasty in 60 patients with various coronary syndromes and culprit lesions that were not totally occlusive. Lesions were classified angiographically according to Ambroses criteria as concentric, type I and II eccentric, and multiple irregularities, or as complex or noncomplex, and then compared with the corresponding angioscopic findings. Disruption and/or thrombus were seen in 17 of 19 type II eccentric lesions and 21 of 23 angiographically complex lesions and had the highest positive predictive value to detect complicated atherosclerotic plaques (type II eccentric lesions: positive predictive value 89%, 95% confidence intervals 67% to 99%; complex lesions: 91%, 95% confidence intervals 72% to 99%). We conclude that Ambroses type II eccentric stenoses and angiographically complex lesions are strongly associated with disrupted plaques and/or thrombus as assessed by angioscopy in patients and represent unstable plaque substrates.

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.

Detecting and differentiating white from red coronary thrombus by angiography in angina pectoris and in acute myocardial infarction

To determine the ability to detect thrombus by angiography, angioscopy was performed before angiography in patients undergoing interventional procedures and the data collected in a blinded fashion. These data demonstrated that the sensitivity of angiography to detect white thrombus was 50% and the specificity was 95%, whereas the sensitivity and specificity to detect red thrombus was 100%, respectively; the positive and negative predictive value of detecting thrombus in general was 89% and 83%, respectively.

Stenting for in‐stent restenosis: A long‐term clinical follow‐up

We studied the feasibility, safety, and short‐ and long‐term outcomes of treating coronary in‐stent restenosis with primary restenting. Thirty‐one patients (32 lesions) were treated. Eleven patients had adjunctive rotational atherectomy. Clinical follow‐up was obtained in all 31 patients at a mean of 9.1 ± 5.5 months by direct phone contact with the patients, medical records, and subsequent hospitalization for recurrent symptoms and/or revascularization. There were no cardiac deaths or myocardial infarctions. In native vessels (26 patients), repeat target lesion revascularization was required in eight patients (31%); two other patients (7.7%) had angina and were treated medically. All vein graft lesions had recurrent restenosis. Significant predictors of recurrent clinical events were lesions in vein grafts, multivessel disease, and use of higher poststent deployment inflation pressures. Primary restenting for in‐stent restenosis in native vessels is a safe approach with good short‐term outcome. Recurrent restenosis remains a problem, as it does with other devices, particularly in vein graft lesions and in patients with multivessel disease. Restenting for in‐stent restenosis should probably be used selectively. Cathet. Cardiovasc. Intervent. 48:143–148, 1999.

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.

Diagnosis of Acute Myocardial Infarction on Computed Tomography Angiogram

A 68-year-old white man, an active smoker with hypertension and hyperlipidemia, presented to the emergency department with substernal chest pain. His chest pain began acutely 2 hours earlier, was described as intense pressure radiating to the back, 10/10 in severity with associated diaphoresis, nausea, and vomiting. Chest pain persisted despite sublingual nitroglycerin and subsequent intravenous nitroglycerin and morphine. He remained hemodynamically stable, and the results of his clinical examination were unremarkable. His initial ECG demonstrated nonspecific ST-segment changes (Figure 1). Serial ECGs remained unchanged; a posterior ECG was not performed. Initial cardiac enzymes were also nondiagnostic. …

961-80 Surface Laplacian ECG Maps Provide a Sensitive and Localizing Measure of Cardiac Ischemia

To test the hypothesis that Laplacian surface electrocardiography provides a sensitive and local measure of coronary ischemia, we studied six consecutive patients undergoing balloon angioplasty. Three self-adhesive pads of electrodes containing 84 multipolar Laplacian electrodes were applied to the anterior and left-lateral thorax. Laplacian electrograms and a standard 12 lead ECG were recorded prior to and during each balloon inflation. The ratio of ST segment shift to baseline ORS amplitude (ST/O) was computed for the Laplacian electrodes and the standard 12 leads. Defining ST/O = 0.1 to be the minimum significant ST shift, Laplacian maps in all six patients revealed a significant ST shift during balloon inflation while the 12 lead ECG revealed a significant 5T shift in only three patients. The mean peak value of ST/O in the Laplacian maps was 0.40 versus 0.13 in the 12 lead ECG (p = 0.01). Laplacian maps of ST/O showed localized elevation over the expected region of distribution of the occluded vessel, often surrounded by a region of negative ST/O. The unipolar leads revealed a diffuse bipolar pattern of ST segment shift. Conclusion Body surface Laplacian mapping may provide a sensitive and accurate noninvasive means of detecting and localizing cardiac ischemia, superior to the 12 lead ECG. Download high-res image (105KB) Download full-size image Laplacian ST/O map during distal left anterior descending coronary artery occlusion.