Role of Transesophageal Echocardiography in the Evaluation of Patients with Clinical Pacemaker Syndrome

Objectives: The goal of this study was to investigate the possible role of transesophageal echocardiography in the evaluation of patients with clinical pacemaker syndrome. Background: While several reports on transthoracic echocardiographic features of ventricular pacing were described, no previous study of transesophageal echocardiography has been undertaken in patients at the severe end of pacemaker syndrome who need to reprogramming dual chamber pacing for symptom relief. Methods: Twelve VVI patients with clinical symptomatic pacemaker syndrome (Group I) and 10 VVI patients without pacemaker syndrome (Group II ) were prospectively studied. The two groups were pacemaker dependent and persistent ventriculoatrial conduction. Transesophageal echocardiographic parameters were assessed in Group II and within 6 hours before reprogramming to the DDD mode in Group I. Follow-up transesophageal echocardiographic study was performed 28 ± 5 days after reprogramming in Group I. Results: All patients in Group I had subjective improvements of symptoms after DDD reprogramming. The atrial reverse flow velocities of pulmonary veins in Group I before reprogramming were significantly higher compared with in Group II (39.3 ± 11.4 vs. 15.7 ± 13.5 cm/sec, P < 0.0001). Spontaneous echo contrast in the descending aorta was detected in all patients from Group I before reprogramming. The prevalence of significant mitral regurgitation (3 moderate) was significantly higher in Group I before reprogramming than in Group II (67% vs. 8%, P = 0.01). Significant mitral regurgitation and spontaneous echo contrast in the descending aorta in Group I disappeared after reprogramming to the DDD mode. Conclusions: Transesophageal echocardiography provides physiological, pacemaker-related hemodynamic changes in paced patients. Significantly higher atrial reverse flow velocities of pulmonary veins, increased frequency of spontaneous echo contrast in the descending aorta and significant mitral regurgitation are peculiar echocardiographic findings in VVI patients with clinical pacemaker syndrome.