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BackgroundPacing the right ventricle is established practice, but there remains controversy as to the optimal site to preserve hemodynamic function.AimsTo evaluate clinical and hemodynamic differences between apical and septal pacing in pacemaker-dependent patients.MethodsPatients receiving their first pacemaker for advanced atrioventricular block, with the atria in sinus rhythm, were randomized to receive apical (Group A) or septal (Group S) ventricular leads. After implant, with the device programmed VVI 70 beats/min fixed rate, patients underwent a 6-minute walk test and a transthoracic echocardiogram. Then, DDDR was programmed at nominal settings. The same tests were performed at 6 months and 12 months follow-up. If ventricular pacing was less than 98%, the patient was excluded.ResultsA total of 142 patients were included in the study. During the study year, 71 (50%) were excluded for not fulfilling the condition of 98% ventricular pacing. Groups A and S had 34 and 37 patients, respectively. Age and gender were similar in the groups. At implant, QRS duration was significantly greater in Group A (158 ms) than Group S (146 ms; P = 0.018), and the QRS axis was different: –74.5° in Group A and 1° in Group S (P < 0.001). At 1 year, the 6-minute walk improved significantly in both groups: Group A 15% (P = 0.048) and Group S 24% (P = 0.001). Left ventricular ejection fraction (LVEF) increased from 0.57 to 0.61 (P = 0.008) in Group S, without significant change in Group A.ConclusionsAfter 1 year, pacemaker-dependent patients with septal ventricular leads have better clinical and functional (LVEF) outcome.

Mediastinitis after cardiac surgery is difficult to diagnose in many cases. The transitory epicardial pacing wires used after surgery are placed in the mediastinum, so the culture of these wires could be useful for the diagnosis of this disease. To test this hypothesis, we routinely cultured the epicardial pacing wires of 565 patients undergoing extracorporeal circulation. Wires were removed on the 7th to 9th postoperative day under sterile conditions and were cultured with routine techniques used for the culture of venous catheters. Mediastinitis developed in 16 patients, and Staphylococcus aureus was the most common pathogen (81.25%). We had 103 positive and 462 negative cultures. There were 458 true-negative, 12 true-positive, 91 false-positive and 4 false-negative results. For mediastinitis in general, epicardial pacing wire culture has a sensitivity of 75%, specificity of 83.4%, positive predictive value of 11.6%, and negative predictive value of 99.1%. For Staphylococcus aureus mediastinitis, epicardial pacing wire culture has a sensitivity of 84.6%, specificity of 95.8%, positive predictive value of 32.3%, and negative predictive value of 99.6%. We conclude that a sterile culture of the epicardial pacing wires strongly contradicts a diagnosis of postsurgical mediastinitis.