Introduction: Persistent left superior vena cava (PLSVC) is the most comman venous congenital malformation. Positioning of pacemaker (PM) leads through PLSVC may be challenging. We report three patients with PLSVC who had PM/ICD implantation at our center.
Case report: In a prospective single-center observational study, 609 patients underwent transvenous ICD implantation without intraoperative testing. Defibrillation efficacy was validated prior to hospital discharge by applying two 10 J safety margin shocks.
Results: Case 1. A 58 year-old-woman with dilated cardiomyopathy was admitted to our hospital with symptoms of congestive heart failure. ECG showed normal sinus rhythm and left bundle branch block with a QRS duration of 140 ms. Echocardiography demonstrated severe left ventricular (LV) dilatation. LV ejection fraction and end diastolic diameter were 32% and 64 mm, respectively. Biventricular ICD was recommended. During implantation, PLSVC and absence of right SVC were diagnosed by venography. Active fixation defibrillation lead was screwed in to RVOT. Active fixation atrial lead was screwed in to right atrium anterolateral wall. Balloon occlusion coronary sinus (CS) angio was not possible because of huge size of the CS. We performed left coronary angiography (CAG) to see the CS branches. After CAG, we could be able to cannulate posterior branch of CS. However, LV lead implantation was not possible due to high pacing threshold, diaphragmatic stimulation and unstable lead position. Therefore, LV lead was implanted epicardially after several days. She was asymptomatic and lead measuraments were found normal during follow up. Case 2. 20-year-old man was admitted to our hospital with palpitation and syncope. Physical examination was normal. ECG showed sinus bradicardia. Echocardiography was normal. Holter ECG revealed long sinus pauses during symptomatic periods. We have recommended a dual chamber pacemaker. At the time of left subclavian puncture, PLSVC was found. We decided to perform the procedure through a right subclavian approach. A DDD-R pacemaker was implanted through right subclavian vein. Case 3. A 70-year-old man with a diagnosis of sick sinus syndrome was referred to our clinic for pacemaker implantation. ECG showed normal sinus rhythm. Echocardiography revealed mild mitral regurgitation with normal systolic function. Holter ECG findings were compatible with sick sinus syndrome. At the time of left subclavian vein puncture, PLSVC and absence of right SVC were diagnosed by venography. A DDD-R pacemaker was implanted through left subclavian vein
Conclusions: Implantation of PM/ICD leads is very challenging in patients with PLSVC. The implantation procedure may be even more complicated in patients with PLSVC and absence of right SVC. The diagnosis can be confirmed easily by contrast venography. Device implantation by using several approaches is possible in these patients.