ABSTRACT
BACKGROUND: Nonischemic dilated cardiomyopathy (NICM) is associated with diffuse global hypokinesia on echocardiography. However, NICM also may be associated with segmental wall-motion abnormalities (SWMAs) even in the presence of global hypokinesia, probably secondary to patchy myocardial scars. OBJECTIVE: Because myocardial scars serve as substrate for reentry, the purpose of this study was to determine whether SWMA is a predictor of ventricular arrhythmic events in NICM. METHODS: Echocardiographic parameters and appropriate implantable cardioverter-defibrillator (ICD) therapy for arrhythmic events (shock or antitachycardia pacing) were studied in NICM patients with an ICD. Two-dimensional echocardiography of the left ventricle was recorded in a 16-segment model. SWMA was defined by the presence of akinesia or moderate to severe hypokinesia in at least two segments. Patients were divided into one of two groups according to the presence (SWMA group) or the absence (non-SMWA group) of SWMA. RESULTS: SWMA was present in 47.5% of 101 patients (mean age 58.0 ± 15.6 years, 85% male, primary prophylaxis indication 46%, mean ejection fraction 26% ± 9%, mean follow-up 29 ± 18.4 months) studied. No significant difference in mean age, ejection fraction, and QRS duration was seen between SWMA and non-SWMA groups. The SWMA group had a significantly higher incidence of arrhythmic events than did the non-SWMA group (65% vs 15%, P <.001). Kaplan-Meier survival analysis revealed that SMWA was associated with significantly reduced time to first arrhythmic event (P = .001). SWMA (P <0.001), New York Heart Association heart failure class (P = .016), and secondary prevention indication for ICD placement (P = .005) were significant independent predictors of an arrhythmic event. SWMA did not predict mortality. CONCLUSION: SWMA is an independent predictor of arrhythmic events in patients with NICM.
Subject(s)
Arrhythmias, Cardiac/etiology , Cardiomyopathy, Dilated/physiopathology , Myocardial Contraction , Ventricular Function, Left , Arrhythmias, Cardiac/diagnostic imaging , Arrhythmias, Cardiac/physiopathology , Arrhythmias, Cardiac/therapy , Cardiomyopathy, Dilated/diagnostic imaging , Defibrillators, Implantable , Echocardiography , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Stroke VolumeABSTRACT
BACKGROUND: Patients with left ventricular (LV) systolic dysfunction due to coronary artery disease (CAD) may develop stress-induced wall motion abnormalities (SWMA) with low-dose (10 microg/kg/min) dobutamine infusion. The clinical significance of low-dose SWMA is unknown. OBJECTIVE: We investigated the clinical, hemodynamic and angiographic correlates of low-dose SWMA in patients with chronic ischemic LV systolic dysfunction. METHODS: Seventy patients with chronic ischemic LV systolic dysfunction who had dobutamine stress echocardiography were studied. Clinical, hemodynamic, and angiographic parameters at rest and low-dose were compared between 38 patients (mean ejection fraction (EF) of 30 +/- 8%) with low-dose SWMA and 32 patients (EF 30 +/- 11%) without low-dose SWMA. RESULTS: Multivariate analysis showed that the number of coronary territories with severe disease (stenosis > or =70%)(P = 0.001, RR = 6.3) was an independent predictor of low-dose SWMA. An increasing number of collateral vessels protected patients from low-dose SWMA (P = 0.011, RR = 0.25). A higher resting heart rate was a negative predictor of low-dose SWMA (P = 0.015, RR = 0.92) but no other hemodynamic variables were predictors. In the patients with low-dose SMA, regions with low-dose SWMA were more likely to be supplied by vessels with severe disease than regions without low-dose SWMA (92% vs 58%, P < 0.001). CONCLUSION: In patients with ischemic LV systolic dysfunction, the extent of severe disease and a lower numbers of collaterals predict the occurrence of low-dose SWMA. Low-dose SWMA is a highly specific marker for severe disease.
Subject(s)
Dobutamine/adverse effects , Myocardial Ischemia/chemically induced , Myocardial Ischemia/diagnostic imaging , Ventricular Dysfunction, Left/chemically induced , Ventricular Dysfunction, Left/diagnostic imaging , Cardiotonic Agents/adverse effects , Echocardiography/methods , Female , Humans , Infusions, Intravenous , Male , Middle AgedABSTRACT
We report the prospective use of an electrocardiographic sign--lead aVR ST-segment elevation greater than that seen in lead V(1)--in patients with an acute coronary syndrome as a method to prompt early angiography, to withhold clopidogrel therapy, and to perform urgent coronary bypass surgery leading to successful clinical outcomes.
Subject(s)
Angina, Unstable/diagnosis , Coronary Stenosis/diagnosis , Coronary Stenosis/therapy , Electrocardiography/methods , Platelet Aggregation Inhibitors/therapeutic use , Ticlopidine/administration & dosage , Withholding Treatment , Adult , Aged , Angina, Unstable/etiology , Clopidogrel , Coronary Angiography , Coronary Stenosis/complications , Female , Humans , Male , Middle Aged , Outcome and Process Assessment, Health Care , Predictive Value of Tests , Prospective Studies , Ticlopidine/analogs & derivativesABSTRACT
Totally occluded saphenous vein grafts are difficult to treat percutaneously with a higher likelihood of distal embolization and slow-flow or no-reflow during percutaneous interventions. The PercuSurge system, which utilizes a distal balloon occlusive device, has been shown to improve clinical outcomes during saphenous vein graft (SVG) interventions. This device may not be optimal in the setting of heavy thrombus or debris burden, a situation frequently encountered in totally occluded SVGs. Rheolytic thrombectomy facilitates percutaneous interventions by effectively removing intraluminal thrombus and debris but lacks distal embolization protection. We report our experience with the synergistic use of balloon-based distal embolization protection (PercuSurge) and rheolytic thrombectomy (AngioJet) to optimize percutaneous revascularization of totally occluded SVGs.
