Effect of Pacing Chamber and Atrioventricular Delay on Acute Systolic Function of Paced Patients With Congestive Heart Failure (original) (raw)
Related papers
Journal of the American College of Cardiology, 1995
Objectives. This prospective study assessed the initial hemodynamic effects and long-term clinical benefits of dual-chamber pacing with a short atrioventricular (AV) delay in patients with chronic heart failure who had no traditional indication for pacemaker implantation. Background. Dual-chamber pacing with a short AV delay has been proposed as a nonpharmacologic treatment for drugrefractory heart failure. Both initial and long-term hemodynamic as well as functional benefits have been reported. All previous studies have used an AV delay of 100 ms. Despite encouraging results, these previous studies have been anecdotal and uncontrolled. Methods. This double-blind, randomized, crossover trial included 12 subjects with chronic congestive heart failure despite optimal medical therapy. Patients were required to be in sinus rhythm with no evidence of significant bradyarrhythmias. On the day after implantation of a dual-chamber pacemaker, invasive hemodynamic measurements were made at varying AV delays between 100 and 200 ms. Patients were then randomized to either dual-chamber pacing with a 100-ms AV delay or backup mode (VVI at 40 beats/rain). After 4 to 6 weeks, crossover to the other pacing mode was programmed. Results. Hemodynamic measurements on the day after pacemaker implantation demonstrated no benefit of pacing with any AV delay compared with intrinsic conduction. At the optimal AV interval for each patient, neither cardiac output (4.5-+ 1.5 vs. 4.7-+ 1.6 liters/rain [mean-+ SD]) nor wedge pressure (16-+ 10 vs. 17-+ 8 mm Hg) improved significantly from baseline measurements during intrinsic conduction. The long-term pacing protocol was completed in nine patients. Ejection fraction was 16-+ 6% with dual.chamber (VDD mode) pacing and 18-+ 4% in backup mode (p = NS). No patient had an increase in ejection fraction by >5% with VI)D pacing, nor did any patient improve in New York Heart Association functional class with short AV delay dual-chamber pacing. Also, there were no significant reductions in body weight or diuretic requirements during this pacing period. Conclusions. Dual-chamber pacing with a short AV delay does not improve hemodynamic and clinical status or ejection fraction measured on the day after pacemaker implantation in patients with chronic congestive heart failure. Routine use of pacemaker therapy with a short AV delay as a primary treatment of heart failure in patients without standard arrhythmic indications is unwarranted.
… England Journal of …, 2001
Nine patients were withdrawn from the study before randomization, and 10 failed to complete both study periods. Thus, 48 patients completed both phases of the study. The mean (±SD) distance walked in six minutes was 23 percent greater with active pacing (399±100 m vs. 326±134 m, P<0.001), the qualityof-life score improved by 32 percent (P<0.001), peak oxygen uptake increased by 8 percent (P<0.03), hospitalizations were decreased by two thirds (P<0.05), and active pacing was preferred by 85 percent of the patients (P<0.001).
International Journal of Cardiology, 2006
In patients with severe heart failure, sinus rhythm and wide QRS complex biventricular (BiV) pacing leads to clinical and haemodynamic improvement, but the immediate reversibility of these changes is not known. We assessed the acute and medium-term (3-month) haemodynamic effects of BiV pacing and of switching to other pacing modalities in 21 patients with severe heart failure, sinus rhythm and QRS&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=130 ms. Haemodynamic studies were performed: 1) at the time of implantation of a BiV pacing device, during AAI pacing, atrial synchronous right ventricular (RV) pacing, atrial synchronous left ventricular (LV) pacing and atrial synchronous BiV pacing (all at 100 bpm); 2) after 3 months of continuous BiV pacing--with evaluations being made by switching to RV and the other pacing modalities. At both the acute and medium-term evaluations, BiV pacing provided the greatest improvement in cardiac index. Switching from BiV to RV pacing led to a more marked decrease in the cardiac index at 3 months. No strict correlation was evident between acute and medium-term effects of BiV pacing on cardiac index. Cardiac resynchronization by BiV pacing provides acute/medium-term improvements in cardiac index. Sudden, medium-term failure of LV stimulation can lead to an even more pronounced haemodynamic derangement than that inducible by RV pacing at baseline. Acute haemodynamic evaluations do not seem to provide a powerful way for identifying medium-term responders.
Critical Care, 2009
Introduction There is considerable uncertainty about the reproducibility of the various instruments used to measure dyspnea, their ability to reflect changes in symptoms, whether they accurately reflect the patient's experience and if its evolution is similar between acute heart failure syndrome patients and nonacute heart failure syndrome patients. URGENT was a prospective multicenter trial designed to address these issues. Methods Patients were interviewed within 1 hour of first physician evaluation, in the emergency department or acute care setting, with dyspnea assessed by the patient using both a five-point Likert scale and a 10-point visual analog scale (VAS) in the sitting (60º) and then supine (20º) position if dyspnea had not been considered severe or very severe by the sitting versus decubitus dyspnea measurement. Results Very good agreements were found between the five-point Likert and VAS at baseline (0.891, P <0.0001) and between changes (from baseline to hour 6) in the five-point Likert and in VAS (0.800, P <0.0001) in acute heart failure (AHF) patients. Lower agreements were found when changes from baseline to H6 measured by Likert or VAS were compared with the seven-point comparative Likert (0.512 and 0.500 respectively) in AHF patients. The worse the dyspnea at admission, the greater the amplitude of improvement in the first 6 hours; this relationship is stronger when dyspnea is measured with VAS (Spearman's rho coefficient = 0.672) than with the five-point Likert (0.272) (both P <0.0001) in AHF patients. By the five-point Likert, only nine patients (3% (1% to 5%)) reported an improvement in their dyspnea, 177 (51% (46% to 57%)) had no change, and 159 (46% (41% to 52%)) reported worse dyspnea supine compared with sitting up in AHF patients. The PDA test with VAS was markedly different between AHF and non-AHF patients. Conclusions Both clinical tools five-point Likert and VAS showed very good agreement at baseline and between changes from baseline to tests performed 6 hours later in AHF patients. The PDA test with VAS was markedly different between AHF and non-AHF patients. Dyspnea is improved within 6 hours in more than threequarters of the patients regardless of the tool used to measure the change in dyspnea. The greater the dyspnea at admission, the greater the amplitude of improvement in the first 6 hours.
The American Journal of Cardiology, 2003
S everal groups have studied whether further clinical benefit can be realized by "optimizing" programmed atrioventricular (AV) delay in patients with DDD pacemakers and left ventricular dysfunction, but to date no significant benefit has been clearly demonstrated. 1-10 Various techniques have been used to determine optimal AV delay in patients with DDD pacemakers, including Doppler echocardiography, nuclear techniques, and invasive hemodynamic measurements. 4 -10 We report the results of a double-blind trial in which optimal AV delay was determined using Doppler echocardiography and invasive hemodynamic measurements, and then compared these results with the "out of the box" AV delay in a crossover fashion in patients with dilated cardiomyopathy and permanent DDD pacemakers implanted for symptomatic bradycardia. The purpose of our study was to determine if "optimal" AV delay resulted in a symptomatic and functional benefit greater than that provided by the device's nominal AV delay.