Sudden cardiac arrest as a presenting symptom of mitral valve prolapse.

Mitral valve prolapse (MVP) is a common and predominantly benign condition; however, occasional reports of cardiac arrest in individuals with MVP have raised concern for a malignant subtype. The risk of sudden cardiac arrest in MVP is twice as high as that in the general population. The exact aetiology and risk predictors are elusive, but identification is necessary, if we are to protect patients at risk for cardiac arrest. This report highlights cardiac arrest as the initial presenting symptom of MVP. Rapid initiation of bystander cardiopulmonary resuscitation and time to first shock are key predictors of prognosis. Better screening to identify individuals with malignant phenotypes may aid in reducing the morbidity and mortality in patients with a predisposition for life-threatening arrhythmias.

Electrophysiological effects and clinical utility of propafenone in children.

AIM: This retrospective case series study sought to describe the safety and clinical effectiveness of propafenone for the control of arrhythmias in children with and without CHD or cardiomyopathy. METHODS: We reviewed baseline characteristics and subsequent outcomes in a group of 63 children treated with propafenone at 2 sites over a 15-year period Therapy was considered effective if no clinically apparent breakthrough episodes of arrhythmias were noted on the medication. RESULTS: Sixty-three patients (29 males) were initiated on propafenone at a median age of 2.3 years. CHD or cardiomyopathy was noted in 21/63 (33%). There were no significant differences between demographics, clinical backgrounds, antiarrhythmic details, side effect profiles, and outcomes between children with normal hearts and children with CHD or cardiomyopathy. Cardiac depression at the initiation of propafenone was more common amongst children with CHD or cardiomyopathy compared to children with normal hearts. Systemic ventricular function was diminished in 15/63 patients (24%) prior to starting propafenone and improved in 8/15 (53%) of patients once better rhythm control was achieved. Other than one child in whom medication was stopped due to gastroesophageal reflux, no other child experienced significant systemic or cardiac side effects during treatment with propafenone. Propafenone achieved nearly equal success in controlling arrhythmias in both children with normal hearts and children with congenital heart disease or cardiomyopathy (90% versus 86%, p = 0.88). CONCLUSION: Propafenone is a safe and effective antiarrhythmic medication in children.

Epicardial Ablation of Persistent Junctional Reciprocating Tachycardia in an Infant With Tachycardia-Induced Cardiomyopathy.

A 3-month-old infant who developed persistent junctional reciprocating tachycardia (PJRT)-induced cardiomyopathy that was successfully treated with radiofrequency ablation. To our knowledge this is the youngest reported patient with a successful epicardial lesion placed in a diverticulum off the coronary sinus and also the first report of a PJRT connection located at an epicardial site distinct from the mitral and tricuspid valve annulus. We use this case to highlight how low-power lesions in the coronary sinus in the youngest of patients can achieve results safely. (Level of Difficulty: Advanced.).

Case of WPW and anomalous right coronary in a teenager with cardiac symptoms.

A 17-year-old African-American man was being followed for palpitations and chest pain. CT angiography revealed an anomalous right coronary artery from the left coronary sinus and he underwent unroofing of the right coronary ostium. There was a manifest pre-excitation on postoperative ECGs, and review of prior ECGs at initial presentation showed subtle pre-excitation suggesting a left lateral pathway. An electrophysiology study revealed easily inducible supraventricular tachycardia (SVT) and rapid anterograde conduction via the pathway which was successfully ablated. Eight months postablation, the patient remains asymptomatic with no evidence of pre-excitation on ECG.