Mental stress hemodynamic responses and myocardial ischemia: does left ventricular dysfunction alter these relationships?

OBJECTIVE: To assess if mental stress hemodynamic responses are impaired and related to mental stress (MS) ischemia in patients with left ventricular (LV) dysfunction. BACKGROUND: Impaired LV function is an important coronary artery disease (CAD) risk factor and hemodynamic characteristics play an important role in clinical outcomes. Patients with severe LV dysfunction (SLVD) are frequently excluded from prior studies and the effects of LV dysfunction on MS hemodynamic responses are not known. METHODS: Fifty-eight patients with CAD, consisting of 22 patients with normal LV function (ejection fraction (EF) > or =50%), 16 patients with mild-to-moderate LV dysfunction (30% < EF < 50%), and 20 patients with severe LV dysfunction (EF < or =30) underwent bicycle exercise (EX) and MS testing with 12-lead electrocardiogram and monitoring of vital signs on consecutive days in random order. Blood pressure and heart rate (HR) measurements were obtained. Ischemia was measured using single photon emission computed tomography. RESULTS: Both MS and EX produced significant increases in all hemodynamic measurements. HR levels were higher both at rest and during MS in SLVD patients. LV groups increased similarly from rest to stress (both MS and EX) for all measurements except HR during MS, which increased more in patients with SLVD than patients with normal LV function. Hemodynamic responses to MS were not related to myocardial ischemia or heart failure symptoms. CONCLUSIONS: HR response during MS is increased in patients with SLVD, whereas blood pressure responses are similar to those in patients with preserved LV function. Hemodynamic reactivity is unrelated to MS-induced ischemia.

Comparison of mental stress-induced myocardial ischemia in coronary artery disease patients with versus without left ventricular dysfunction.

To examine the susceptibility to myocardial ischemia with mental stress in patients who have coronary artery disease and normal left ventricular (LV) function versus those who have impaired LV function, we examined 58 patients who had coronary artery disease, including 22 who had normal LV function (ejection fraction >/=50%), 16 who had mild to moderate LV dysfunction (ejection fraction 30% to 50%), and 20 who had severe LV dysfunction (ejection fraction 3. At comparable double products across the 3 groups, ischemia was induced with mental stress more frequently in patients who had severe LV dysfunction (50%) than in those who had normal LV function (9%; p <0.01). The frequency of exercise-induced ischemia was different only between those who had mild/moderate LV dysfunction and those who had normal LV function (56% vs 18%, respectively, p <0.05). The pattern of mental stress versus exercise ischemia differed between groups (p <0.02): there was a higher prevalence of mental stress ischemia versus exercise ischemia in patients who had severe LV dysfunction (p = 0.06), a marginally higher prevalence of exercise versus mental stress ischemia in those who had moderate LV dysfunction (p = 0.07), and no difference in mental stress versus exercise ischemia in those who had normal LV function. Thus, at comparable double products during mental stress and similar extent of coronary artery disease, ischemia with mental stress was induced more frequently in patients who had severe LV dysfunction than in those who had normal LV function. These data suggest that mental stress ischemia may be of particular clinical importance in patients who have coronary artery disease and LV dysfunction.

Percutaneous catheter ablation treatment of recurring atrial arrhythmias after surgical ablation.

BACKGROUND: Surgical ablation for atrial fibrillation is associated with early and late recurrence of atrial arrhythmias. Although early arrhythmias may be controlled with conventional treatment, late arrhythmias are often highly symptomatic and relatively hard to manage with antiarrhythmic drugs and electrical cardioversion. This study explores a single-center experience with catheter ablation to treat late failures (>3 months) after surgery. METHODS: This is a prospective longitudinally designed study assessing all patients who underwent surgical treatment for atrial fibrillation as a standalone or concomitant with other procedures by multiple surgeons. All patients were monitored according to the Heart Rhythm Society guidelines. RESULTS: From January 2005 to present, 400 consecutive patients operated on by multiple surgeons were enrolled. The overall success rate per the Heart Rhythm Society guidelines was 87% and 84% (off antiarrhythmic drugs, 78% and 73%) at 12 and 24 months, respectively. Sixteen patients (4%) were referred for electrophysiology study after the surgical procedure (15 Cox-maze III or IV, 1 pulmonary vein isolation). The average age was 61.1+/-15.2 years; the mean left atrium size was 5.1+/-0.7 cm; and the mean time to ablation was 16.9+/-10 months. In 16 patients radiofrequency ablation was applied to treat the following atrial arrhythmias: 7 right atrial flutter or tachycardia, 3 left atrial flutter, 1 biatrial flutter, and 5 left atrial tachycardia. Six patients required a subsequent radiofrequency ablation intervention including 4 patients who required atrioventricular nodal ablations. The long-term success rate for the subsequent catheter ablation in these 16 patients (follow-up of 42.9+/-9.8 months) determined by the rate of sinus rhythm as captured by electrocardiography was 94%. Fifty-three percent of the patients (n=8) in sinus rhythm were still taking antiarrhythmic drugs; 8 patients remained on warfarin. There was 1 late noncardiac death and no late strokes. CONCLUSIONS: In a certain subset of patients, unsuccessful surgical ablation of atrial fibrillation may result in symptomatic atrial arrhythmia. If indicated, catheter ablation is a safe and effective intervention with a relatively high success rate. The combination of the two treatment modalities, catheter and surgical ablation, can improve the outcome even in complex patients.