Methods and Results: All consecutive patients undergoing CRT implantation (de novo implantation or upgrade procedures) at two tertiary centers in Germany and Switzerland were retrospectively screened for the presence of PLSVC. A total of six male patients (median age: 69 years, IQR 11) with PLSVC (Schummer classification type II: n=1; type IIIa: n=0; type IIIb: n=4; unknown: n=1) were identified. CRT implantation was successfully performed in 5 of 6 patients (right sided approach: n=2, left sided approach: n=3). CRT implantation was omitted in a patient with a PLSVC type II due to prolonged procedure duration and frailty. Median procedure duration was 152 min (IQR 76 min), median area dose product was 1200cGy cGy*cm2 (IQR 3249 cGy*cm2). Successful CRT implantation was achieved by using conventional CS cannulation and subselection catheters of different vendors. An active fixation CS lead was used in two patients with left sided CS lead implantation. Median left ventricular sensing was 18 mV, median left ventricular threshold was 1.1 V (pulse duration of 0.5 ms). Follow-up data were available in five patients with a median follow-up of 5 months. Median QRS duration could be reduced from 150 ms (IQR 5 ms) prior to CRT implantation to 130 ms (IQR 26 ms) after CRT implantation. LV systolic function improved from a median of 30 to 45%. Serious complications occurred in one patient (16%) with CS lead dislocation followed by RV lead dislocation with cardiopulmonary resuscitation after the second surgery, complicated by a pneumothorax. The main difficulties encountered during CS lead placement our cohort were a) unawareness of the presence and different types of this venous anomaly, b) difficult selective coronary sinus angiography and no opportunity for retrograde occlusion coronary sinus angiography and c) obtaining a stable coronary sinus lead position in the dilated coronary veins.
Conclusion: Conventional CRT implantation - from either the left or right side - is feasible in patients with different types of PLSVC. Specialized tools to visualize the target vein and active fixation leads seem to be important for successful implantation in these patients. In patients with a known PLSVC and an existing right-sided vena cava superior, a right-sided approach might be preferred.
Figure 1: Initial non-selective angiography in case 4 of 6showing a largely dilated CS outlined by the dotted lines (A). Subselection catheter with a guide wire in a target vein (B). The dotted lines highlight the angiography confirming the presence of an isolated PLSVC with the guide wires and the ICD lead already in place from the right-sided approach (C). Trauma spiral CT scan with 3D reconstruction showing the venous anomaly (D and E). Chest X-ray after dual chamber ICD implantation (F).
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