Atrial lead placement at the lower atrial septum: a potential strategy to reduce unnecessary right ventricular pacing.

AIMS: Right ventricular (RV) pacing has been shown to be potentially detrimental to left ventricular function. In conventional dual-chamber pacing the position of the atrial lead could influence duration of the atrio-ventricular (AV) intervals, which is one of the variables that could be associated with an increased percentage of RV pacing. We wanted to see if lead placement at selected atrial septal sites could reduce AV intervals in patients receiving a dual-chamber pacemaker or implantable cardioverter defibrillator. METHODS AND RESULTS: This was a prospective, acute, randomized single centre study that enrolled 57 patients. The atrial lead was placed in both the right atrial appendage (RAA) and the lower atrial septum (LAS) in each patient in random order. The P-wave durations, PR intervals, A sense-V sense (As-Vs), and A pace-V sense (Ap-Vs) intervals were measured at both atrial lead locations in each patient during device implant. The P-wave durations during sinus rhythm (SR), RAA pacing, and LAS pacing were 113 ± 19, 144 ± 27, and 84 ± 12 ms (RAA vs. LAS, P < 0.001), respectively. The PR intervals during SR, RAA pacing, and LAS pacing were 195 ± 47, 230 ± 61, and 167 ± 44 ms (RAA vs. LAS, P < 0.001), respectively. The As-Vs interval was 31% shorter in LAS pacing than in RAA pacing (134 ± 44 ms vs. 194 ± 52 ms, P < 0.001). The Ap-Vs interval was 24% shorter during LAS pacing than during RAA pacing (195 ± 45 ms vs. 257 ± 63 ms, P < 0.001). CONCLUSION: When compared with RAA pacing, LAS pacing was associated with a shorter P wave duration, PR interval, As-Vs, and Ap-Vs intervals. The potential long-term impact of the strategy of pacing from LAS in reducing unnecessary RV pacing needs to be explored in future studies.

Epinephrine-induced posterior reversible encephalopathy syndrome: a case report.

Posterior reversible encephalopathy syndrome (PRES) is a rare disorder that is usually associated with hypertensive crises. It is often missed but may be diagnosed by head computed tomographic (CT) scan or magnetic resonance imaging. An adolescent man presented for elective right shoulder arthroscopic bankart repair. Arthroscopy was performed using a solution of normal saline with 3.3 mg/L of epinephrine for irrigation. Postoperatively, the patient presented with hypertension and epileptiform activity. A CT scan of the head showed PRES.

Minimally invasive coronary artery bypass grafting: dual-center experience in 450 consecutive patients.

BACKGROUND: Minimally invasive coronary artery bypass grafting (MICS CABG) is a novel coronary operation that does not require infrastructure and is potentially available to all cardiac surgeons. It aims at decreasing the invasiveness of conventional CABG while preserving the applicability and durability of surgical revascularization. We examined the feasibility and safety of MICS CABG in the first large series of this operation to date. METHODS AND RESULTS: All myocardial territories are accessed via a 4- to 6-cm left fifth intercostal thoracotomy. An apical positioner and epicardial stabilizer are introduced into the chest through the subxyphoid and left seventh intercostal spaces, respectively. The left internal thoracic artery is used to graft the left anterior descending artery, and radial artery or saphenous vein segments are used to graft the lateral and inferior myocardial territories. Proximal anastomoses are performed directly onto the aorta or from the left internal thoracic artery as a T-graft. In the first 450 consecutive MICS CABG procedures at our 2 centers, mean+/-SD age was 62.3+/-10.7 years and 123 patients were female (27%). The average number of grafts was 2.1+/-0.7, with complete revascularization in 95% of patients. There were 34 patients in whom cardiopulmonary bypass was used (7.6%), 17 conversions to sternotomy (3.8%), and 10 reinterventions for bleeding (2.2%). Perioperative mortality occurred in 6 patients (1.3%). CONCLUSIONS: MICS CABG is feasible and has excellent procedural and short-term outcomes. This operation could potentially make multivessel minimally invasive coronary surgery safe, effective, and more widely available.

Interferon-ribavirin-associated ischemic colitis.

Interferon-alpha and ribavirin are widely used treatments for chronic hepatitis C. It is believed to be a cytokine made by T lymphocytes upon activation by foreign antigens. Complications of interferon and ribavirin therapy include systemic flulike symptoms, marrow suppression, emotional liability, auto immune reactions (especially auto immune thyroiditis) and miscellaneous side effects such as alopecia, rashes, diarrhea, numbness, and tingling of the extremities. With the possible exception of autoimmune thyroiditis, all these side effects are reversed upon dose lowering or cessation of therapy. We report a case of a 51-year-old man, with no previous history of vascular disease, who developed ischemic colitis after interferon-alpha and ribavirin therapy for chronic hepatitis C. In the literature, there have been only 2 published accounts associating interferon-alpha use with ischemic colitis in 2 patients. This report illustrates a better association of interferon-alpha and ribavirin with ischemic colitis.

Placement of a pacing lead at the inferior portion of the interatrial septum without special tools.

INTRODUCTION: Previous studies have suggested that, among septal sites, the inferior portion of the interatrial septum (IAS) is the most likely to prevent atrial fibrillation, though inserting an active fixation lead at this site can be tedious and time consuming. We describe a relatively straightforward technique to insert a lead at this site without special tools. METHOD: We studied 117 consecutive patients (mean age = 76 +/- 8 years, 69% men) with ACC/AHA class I and II pacing indications and histories of paroxysmal or permanent atrial fibrillation, undergoing implantation of a dual chamber pacing system. A technique using the "preshaped" stylet and fluoroscopic guidance is described. RESULTS: The insertion was successful in 111 patients (95%). Acute dislodgement occurred in six patients (5%). The intrinsic P-wave duration was 117 +/- 22 ms, and the paced P-wave duration was 90 +/- 20 ms (23% shortening, P < 0.001). The mean time required to insert the atrial lead was 12 +/- 8 minutes. No complications occurred. CONCLUSIONS: Insertion of an active fixation lead at the inferior portion of the interatrial septum was safe and highly successful in the majority of patients with this technique.

Transvenous dual site left ventricular pacing plus biventricular pacing for the management of refractory ventricular tachycardia.

This is a case report of a male patient with nonischemic cardiomyopathy who had severely depressed left ventricular systolic function and functional class III congestive heart failure (CHF). He also had left bundle branch block (LBBB) and recurrent ventricular tachycardia (VT). Though the patient's CFH functional class improved after implantation of a transvenous biventricular ICD system, recurrent VT episodes required the initiation of amiodarone. After an improved condition for 28 months, recurrent VT episodes led to multiple consecutive ICD shocks, which constituted an electrical storm and a battery status of elective replacement indicator (ERI). The recurrent VT episodes were suppressed with intravenous amiodarone and lidocaine. As Radiofrequency ablation was declined by the patient, a new left ventricular (LV) lead was transvenously added, providing biventricular and dual site LV pacing. After this intervention the arrhythmia subsided and the intravenous antiarrhythmic medications were stopped. No episodes of sustained VT leading to ICD shocks were observed for the following 9 months. The events in this case suggest that dual site LV pacing with biventricular pacing could be an alternative strategy for the management of refractory VT.