Takotsubo cardiomyopathy and QT interval prolongation: who are the patients at risk for torsades de pointes?

OBJECTIVES: QT interval prolongation is prevalent among patients with Takotsubo cardiomyopathy (TC), whereas torsades de pointes (TdP) has rarely been reported in these patients. We studied all peer-reviewed reports on TC-associated QT interval prolongation and all peer-reviewed reports on TC-associated TdP to characterize the clinical circumstances leading to TdP in patients with TC. METHODS: The literature search yielded 14 reports on TC-associated TdP and 26 reports on TC-associated QT interval prolongation. Overall, 15 patients with TC-associated TdP and 86 patients with TC-associated QT interval prolongation were reported. We systematically reviewed each report and recorded the risk factors for TdP as well as the clinical circumstances of TC. RESULTS: The prevalence of the male sex was higher among patients with TC-associated TdP relative to patients with TC-associated QT interval prolongation (26.7% vs 5.8%; P = .01). There was a trend in the mean maximal corrected QT interval being longer among patients with TC-associated TdP relative to patients with TC-associated QT interval prolongation (679.9 +/- 230.6 vs 555.9 +/- 63.8 milliseconds; P = .06). There were no differences between patients with TC-associated TdP and patients with TC-associated QT interval prolongation in mean age, maximal troponin levels, and lowest ejection fraction. Overall, 12 (80.0%) patients with TC-associated TdP had risk factors for TdP other than the female sex and systolic dysfunction, including suspicion of congenital long QT syndrome, bradycardia, hypokalemia, recent conversion from atrial fibrillation to sinus rhythm, and using QT prolonging agents. CONCLUSIONS: Men with TC-associated QT interval prolongation are at risk for TdP. Most patients with TC-associated TdP have risk factors for TdP other than the female sex and systolic dysfunction.

Vigilance, awareness and a phone line: 20 years of expediting CPR for enhancing survival after out-of-hospital cardiac arrest. The 'SHL'-Telemedicine experience in Israel.

OBJECTIVES: The only large-scale report (1988) by the Israeli national ambulance service Magen David Adom (MDA) on the outcome of cardiac arrest victims who underwent cardiopulmonary resuscitation (CPR) by paramedics called for more frequent and more promptly initiated CPR and shorter time to arrival of paramedic care to improve survival. We report the 1987-2007 experience of resuscitation of out-of-hospital cardiac arrest victims who were 'SHL'-Telemedicine subscribers and who underwent CPR by SHL-Telemedicine mobile intensive care units (MICUs) personnel or under their instructions. METHODS: 'SHL's records of MICU reports and specifics of CPR maneuvers and outcome of resuscitated patients, as recorded by its MICU physicians, were analyzed to determine whether the system enhanced survival. RESULTS: A total of 1810 'SHL'-Telemedicine subscribers (mean age 76+/-12 years [16-104], 67% males) were resuscitated after cardiac arrest, 597 (33%) were hospitalized and 279 (15.4%) were discharged alive. Factors associated with successful resuscitation included witnessed collapse and documented ventricular fibrillation upon MICU arrival. A history of diabetes, hyperlipidemia, stroke or advanced age adversely affected the outcome. Time from collapse to CPR initiation and duration of CPR correlated significantly with survival. Laymen instructed telephonically by the 'SHL'-Telemedicine center performed CPR on 121 patients: 13 (10%) survived to hospital discharge. CONCLUSIONS: 'SHL'-Telemedicine's policy of bi-monthly contact with its subscribers led to heightened awareness of warning signs and need for rapid summoning of medical assistance in the setting of out-of-hospital sudden cardiac arrest.