Rare case of right ventricular dilatation associated with anomalous pulmonary venous drainage, sinus venosus atrial septal defect and persistent left superior vena cava.

A 34-year-old woman was seen in the emergency department for shortness of breath and chest pain. During a pandemic, it is easy to 'think horses and not zebras', and with a patient presenting with the classic coronavirus symptoms it would have been easy to jump to that as her diagnosis. After a careful history and examination, it became clear that there was another underlying diagnosis. Chest X-ray, echocardiogram and CT scan revealed marked right ventricular dilatation and pulmonary hypertension, alongside a persistent left superior vena cava (PLSVC). Further investigation with cardiac MRI and coronary angiography at a tertiary centre demonstrated that she not only have a PLSVC but also a partial anomalous pulmonary venous drainage and sinus venosus atrial septal defect. This case highlights the importance of considering all differentials and approaching investigations in a logical manner.

High-density mapping-guided corrective HIS bundle pacing after failed CRT upgrade for persistent left superior vena cava.

In patients with persistent left superior vena cava (PLSVC), transvenous device implantation for cardiac resynchronization therapy (CRT) may be challenging. We present a complex case with successful, high-density electroanatomic mapping (EAM) guided corrective His bundle pacing (CHBP) following failed CRT upgrade in a patient with PLSVC, congenital heart disease, and pacing-associated heart failure. CHBP restored physiological conduction in left bundle branch block with complete conduction block leading to clinical improvement and cardiac remodeling. The presented case supports the growing evidence that EAM-guided CHBP may be considered a feasible alternative to conventional CRT when venous anatomy is not favorable for left ventricular lead implantation.

Impact of persistent left superior vena cava on radiofrequency catheter ablation in patients with atrial fibrillation.

AIMS: The impact of persistent left superior vena cava (PLSVC) in atrial fibrillation (AF) patients undergoing radiofrequency catheter ablation (RFCA) is not well known. We performed this analysis to evaluate the electrophysiological characteristics of PLSVC and its role in triggering and maintaining AF. METHODS AND RESULTS: Patients with AF referred to two tertiary hospitals were screened and patients with PLSVC in pre-RFCA imaging studies were enrolled. Among 3967 patients, PLSVC was present in 36 patients (0.9%). There were four morphological types of PLSVC: type 1, atresia of the right superior vena cava (SVC) (n = 2); type 2A, dual SVCs with an anastomosis between right and left SVCs (n = 15); type 2B, dual SVCs without an anastomosis (n = 16); type 3, PLSVC draining into the left atrium (LA; n = 2); and unclassified in one patient. Thirty-two patients underwent RFCA and electrophysiology study focusing on PLSVC: PLSVC was the trigger of AF in 48.4% of patients and the driver of AF in 46.9% of patients. Cumulatively, PLSVC was a trigger or driver of AF in 22 patients (68.8%). Whether to ablate PLSVC was determined by the results of electrophysiology study, and no significant difference in the late recurrence rate was observed between patients who did and did not have either trigger or driver from PLSVC. CONCLUSION: Pre-RFCA cardiac imaging revealed PLSVC in 0.9% of AF patients. This study demonstrated that PLSVC has an important role in initiating and maintaining AF in substantial proportion of patients. Electrophysiology study focusing on PLSVC can help to decide whether to ablate PLSVC.