Richard Webel

Left atrial diameter in nonvalvular atrial fibrillation: An echocardiographic study

BACKGROUND The left atrium (LA) is usually enlarged in patients with nonvalvular atrial fibrillation (AF), but factors associated with LA diameter are incompletely defined. METHODS AND RESULTS This transthoracic echocardiographic cohort study includes 3465 participants with nonvalvular AF in 3 multicenter clinical trials. LA diameter determined by M-mode echocardiography was correlated with clinical and echocardiographic features by cross-sectional multivariate regression analyses. The mean LA diameter was 47 +/- 8 mm, on average 6 mm larger in those with AF at the time of echocardiography than in those with sinus rhythm (48 vs 42 mm, P <. 001). Patient age and body weight were independently predictive of LA diameter (P <.0001), but sex, body surface area, and body mass index were not. The estimated independent contribution of atrial rhythm to LA diameter was approximately 2.5 mm. Prolonged duration of AF, left ventricular dilatation and increased muscle mass, mitral regurgitation, annular calcification, and hypertension were additional independent predictors of LA diameter. CONCLUSIONS Multiple factors appear to contribute to LA enlargement in patients with nonvalvular AF, including the presence and persistence of the dysrhythmia.

Pravastatin prevents clinical events in revascularized patients with average cholesterol concentrations

OBJECTIVES This analysis was carried out to determine if revascularized patients derive benefit from the 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor pravastatin. BACKGROUND The HMG-CoA reductase inhibitors result in substantial reductions in serum cholesterol and stabilization of atherosclerotic plaques in patients with coronary artery disease. METHODS Pravastatin was found to reduce clinical cardiovascular events in the Cholesterol and Recurrent Events (CARE) trial consisting of 4,159 patients with a documented myocardial infarction and an average cholesterol level (mean 209 mg/dl and all <240 mg/dl). A total of 2,245 patients underwent coronary revascularization before randomization including 1,154 patients with percutaneous transluminal coronary angioplasty (PTCA) alone, 876 patients with coronary artery bypass graft (CABG) alone, and 215 patients with both procedures. Clinical events in revascularized patients were compared between patients on placebo and on pravastatin. RESULTS In the 2,245 patients who had undergone revascularization, the primary endpoint of coronary heart disease death or nonfatal myocardial infarction (MI) was reduced by 4.1% with pravastatin (relative risk [RR] reduction 36%, 95% confidence interval [CI] 17 to 51, p = 0.001). Fatal or nonfatal MI was reduced by 3.3% (RR reduction 39%, 95% CI 16 to 55, p = 0.002), postrandomization repeat revascularization was reduced by 2.6% (RR reduction 18%, 95% CI 1 to 33, p = 0.068) and stroke was reduced by 1.5% (RR reduction 39%, 95% CI 3 to 62, p = 0.037) with pravastatin. Pravastatin was beneficial in both the 1,154 PTCA patients and in the 1,091 CABG patients who had undergone revascularization before randomization. CONCLUSIONS Pravastatin reduced clinical events in revascularized postinfarction patients with average cholesterol levels. This therapy was well tolerated and its use should be considered in most patients following coronary revascularization.

Design of a multicenter randomized trial for the stroke prevention in atrial fibrillation study

Individuals with nonvalvular atrial fibrillation are at increased risk of stroke. The Stroke Prevention in Atrial Fibrillation Study is a 15-center randomized clinical trial examining the risks and benefits of low-intensity warfarin (prothrombin time of 1.3-1.8 times control) and aspirin (325 mg/day) in patients with constant or intermittent atrial fibrillation. Candidates for anticoagulation (group I) are randomized to receive warfarin in an open-label fashion, aspirin, or placebo; the last two treatments are given in a double-blind fashion. Warfarin-ineligible patients (group II) are randomized to receive aspirin or placebo in a double-blind fashion. Primary end points are ischemic stroke and systemic embolism. Secondary end points are death, transient ischemic attack, myocardial infarction, and unstable angina pectoris. Analysis is based on the intention-to-treat principle. The anticipated rate of primary end points in patients receiving placebo is 6%/yr. The sample size of 1,644 patients is based on a projected reduction in the rate of primary end points of 50% by warfarin and of 33% by aspirin (beta = 0.2, alpha = 0.05). Patient entry commenced in June 1987 and will continue for 3 years, with an additional year of follow-up. High-risk subsamples identified by clinical and echocardiographic criteria are sought prospectively.

Sensitivity and specificity of two-dimensional echocardiographic signs of mitral valve prolapse

The sensitivity and specificity of previously described 2-dimensional echocardiographic signs of mitral valve prolapse (MVP) were assessed in 70 patients with MVP and in 100 normal control subjects. Specificity of individual signs was uniformly high, ranging from 88% for excessive motion of the posterior mitral ring to 100% for several signs including systolic arching in the parasternal long-axis view, excessive posterior coaptation and diastolic doming of the anterior mitral leaflet. Sensitivity of individual signs was low to moderate, ranging from 1% for whip-like motion of both mitral leaflets to 70% for excessive posterior coaptation of the mitral leaflets in the apical 4-chamber view. The highest sensitivity value (87%) was associated with the presence of systolic arching of 1 or both mitral leaflets in the parasternal long-axis view or systolic bowing of 1 or both mitral leaflets in the apical 4-chamber view or excessive posterior coaptation of the mitral leaflets or a combination. This increase in sensitivity was achieved without sacrificing specificity (97%). Thus, the individual 2-dimensional echocardiographic signs tested possess uniformly high specificity, but only low to moderate sensitivity; however, sensitivity can be markedly enhanced without sacrificing specificity by using selected combinations of echocardiographic signs.

Postpartum myocardial infarction treated with percutaneous transluminal coronary angioplasty

We report herein the first case of acute revascularization by percutaneous transluminal coronary angioplasty (PTCA) in postpartum MI

Observer variation in the echocardiographic diagnosis of mitral valve prolapse

To assess inter- and intraobserver variation in the echocardiographic diagnosis of mitral valve prolapse, three independent observers analyzed M-mode echocardiograms (n = 80) and two-dimensional echocardiograms (n = 65) of patients with a mobile midsystolic click with or without a late or holosystolic murmur. In addition, a control group of 100 normal echocardiograms were interspersed among the echocardiograms of patients with mitral valve prolapse and were then interpreted. Each of the three observers analyzed all M-mode and two-dimensional echocardiograms initially and then 2 weeks later for the presence or absence of mitral valve prolapse. M-mode echocardiographic criteria for mitral valve prolapse consisted of late systolic posterior motion (greater than or equal to 3 mm) of one or both mitral leaflets or holosystolic hammocking (greater than or equal to 3 mm) of one or both mitral leaflets. Two-dimensional echocardiographic criteria for mitral valve prolapse consisted of: posterior systolic arching of one or both mitral leaflets in the parasternal long-axis view, and/or posterior systolic bowing of one or both mitral leaflets in the apical four-chamber view posterior to the plane of the mitral anulus, and/or excessive posterior coaptation of the mitral leaflets in either view flush with or posterior to the plane of the mitral anulus. There was insignificant observer variation both in the M-mode and two-dimensional echo groups, as determined using Cochrans Q test.(ABSTRACT TRUNCATED AT 250 WORDS)

Early angioplasty in patients with acute myocardial infarction complicated by hypotension

Emergency percutaneous transluminal coronary angioplasty was performed in 62 patients with acute myocardial infarction complicated by hypotension. All patients were treated within 12 hours of the onset of chest pain. Angioplasty was completely successful (residual lesion less than or equal to 50%) in 48 patients, partially successful (patent vessel greater than 50% residual lesion) in four patients, and unsuccessful in 10 patients. Patients in whom angioplasty was successful had a hospital mortality rate of 19%; those in whom angioplasty was unsuccessful or only partially successful had hospital mortality rates of 60% and 50%, respectively, (p = 0.012). Patients with occlusion of the proximal left anterior descending vessel had the highest failure rate (42%) and the highest mortality rate (67%). Other univariate predictors of hospital mortality were older age and elevated end-diastolic pressure. Successful emergency angioplasty improves mortality in patients with acute infarction complicated by hypotension.

Emergency angioplasty in acute anterior myocardial infarction

Ninety-three patients with acute anterior myocardial infarction were treated with emergency percutaneous transluminal coronary angioplasty (PTCA). All were found to have a high-grade obstruction in the left anterior descending (LAD) vessel or the bypass graft to this vessel; 64 patients had a total occlusion. A completely successful PTCA, defined as a residual lesion of less than or equal to 50%, was achieved in 73 (78%) patients. A partially successful PTCA, with a residual lesion of 51% to 99%, was achieved in 12 (13%) patients. PTCA was unsuccessful in eight (9%) patients. Hospital mortality was 14%. Three parameters viewed separately each predicted hospital mortality: presence of shock, a proximal location of the LAD vessel occlusion, and the residual stenosis after PTCA. Reocclusion was found in only 11% of patients but 34% had evidence of restenosis on restudy.

Septic thrombophlebitis: percutaneous mechanical thrombectomy and thrombolytic therapies.

Suppurative thrombophlebitis (Lemierres syndrome) of the internal jugular vein is a rare and sometimes fatal complication. It commonly occurs from oropharyngeal infections, peripheral lines, complications from dental procedures, gingivitis, or central venous catheterizations. Empiric antibiotics are the initial treatment of choice followed by thrombolytics or surgical thrombectomy in refractory cases. We present a case of septic thrombophlebitis of the right internal jugular vein from a peripherally inserted central venous catheter. We also review the current percutaneous mechanical thrombectomy and thrombolytics therapies for such a rare disorder. Mechanical thrombectomy includes rotational thrombectomy or rheolytic therapies. Devices include the Amplatz thrombectomy device (Microvena), the Arrow-Trerotola Percutaneous thrombolytic device (Arrow), and the Cragg-Casteneda thrombolytic brush (Microtherapeutics). Rheolytic therapies include Angiojet, the Hydrolyzer, and the Oasis Thrombectomy System. Percutaneous mechanical thrombectomy techniques include rotational fragmentation, aspiration or suction thrombectomy, and hydrodynamic thrombectomy. AngioJet catheters may be used for percutaneous embolectomy in conjunction with pulse spray techniques, which instill thrombolytics locally. Thrombolytics include streptokinase, urokinase, and recombinant-tissue plasminogen activator. Mechanical thrombectomy combined with thrombolytics provide optimal treatment results secondary to their complementary effects. Therefore, patients who are refractory to standard medical therapy and considered poor surgical candidates may benefit from combined percutaneous mechanical thrombectomy with thrombolytics to achieve superior results if no contraindications exist for thrombolytics.

Diagnosis and treatment of spontaneous coronary artery pseudoaneurysm: Rare anomaly with potentially significant clinical implications

Spontaneous coronary artery pseudoaneurysm (PSA, false aneurysm) is an extremely rare occurrence with the precise incidence unknown. It is defined as an outwardly bulging monolayer or double layer within the coronary artery that lacks all 3 layers (intima, media, and adventitia) of the arterial wall. Coronary PSA commonly occurs from arterial dissection or perforation induced by catheter intervention, infection, pregnancy, or trauma. Traumatic dissection or perforation of the coronary artery after a percutaneous coronary intervention (PCI) remains the most common cause. Such cases may progress to myocardial ischemia, acute myocardial infarction, or acute coronary artery rupture causing death from cardiac tamponade.