Coronary Spasm and Polymorphic Ventricular Tachycardia One Year After Takotsubo

Takotsubo Syndrome and Sudden Cardiac Death

Takotsubo syndrome (TTS), triggered by intense emotional or physical stress, occurring most commonly in post-menopausal women, presents as an ST-elevation myocardial infarction (MI). Cardiovascular complications occur in almost half the patients with TTS, and the inpatient mortality is comparable to MI (4-5%) owing to cardiogenic shock, myocardial rupture, or life-threatening arrhythmias. Thus, its prognosis is not as benign as previously thought, as it may cause mechanical complications (cardiac rupture) and potentially lethal arrhythmias and sudden cardiac death (SCD). Similar to MI, some patients may perish before reaching the hospital due to out-of-hospital cardiac arrest; this may lead to underestimation of the actual SCD risk. Furthermore, after discharge, some patients may develop late SCD and/or TTS recurrence that may result in SCD. There are risk factors for SCD in TTS patients, such as severe/persistent QT-interval prolongation inciting torsade-de-pointes, other ECG abnormalities (diffuse giant negative T-waves, widened QRS-complex), bradyarrhythmias, comorbidities, concurrent obstructive coronary artery disease or vasospasm, male gender, older age, severe left ventricular dysfunction, and use of sympathomimetic drugs. All these issues are herein reviewed, case reports/series and data from large cohort studies and meta-analyses are analyzed, risk factors are tabulated, and proarrhythmic effects and management strategies are discussed and pictorially illustrated.

Ventricular arrhythmias in Takotsubo Syndrome: incidence, predictors and clinical outcomes

AIMS

To investigate predictors of the occurrence of subacute ventricular arrhythmias (VAs), defined as any VAs presenting after 48 h from admission in patients with Takotsubo Syndrome (TTS), and to evaluate the related in-hospital mortality.

METHODS

This is a retrospective single-center study enrolling patients admitted between 2012 and 2017 with TTS according to International Takotsubo diagnostic criteria. Data collection included ECG on admission and at 48 h, telemetry monitoring and transthoracic echocardiogram.

RESULTS

We enrolled 93 patients; during in-hospital stay (mean 14 ± 16 days) subacute VAs occurred in 25% of patients (VAs group). Life-threatening VAs occurred in 6% of patients (3 sustained ventricular tachycardia, 1 torsade de pointes, 1 ventricular fibrillation) and not life-threatening VAs in 19% (6 non-sustained ventricular tachycardia and 12 premature ventricular contractions > 2000 in 24 h). Mortality was higher in the VAs than in the non-VAs group (P = 0.03), without differences in terms of life-threatening and not life-threatening subacute VAs (P = 0.65) and VAs on admission (P = 0.25). Logistic regression identified the following independent predictors of subacute VAs occurrence: VAs on admission {odds ratio [OR] 22.5 (3.9-131.8), P = 0.001]}, New York Heart Association (NYHA) class III-IV on admission [OR 6.7 (1.3- 34.0), P = 0.021] and QTc at 48 h [OR 1.01 (1.00-1.03), P = 0.046].

CONCLUSION

TTS patients with VAs and NYHA class III-IV on admission and higher QTc at 48 h are at increased risk of subacute VAs occurrence, associated with higher in-hospital mortality. Awareness of this potential complication is critical for proper patients management.

Pathogenesis of Ventricular Arrhythmias and Its Effect on Long-Term Prognosis in Patients With Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy (TTC), also known as broken heart syndrome, stress cardiomyopathy (SCM), or apical ballooning syndrome, is a non-ischemic cardiac disease with an initial clinical presentation that is very similar to acute coronary syndrome (ACS). Ventricular arrhythmias (VAs) contribute significantly to an increase in the rates of death in patients with TTC, especially during the acute phase, in which patients with TTC are more susceptible to develop life-threatening arrhythmias (LTA) such as ventricular tachycardia (VT), ventricular fibrillation (VF), torsades de pointes (TdP), and sudden cardiac death (SCD). However, the pathophysiology of TTC and how VA occurs are still a mystery. We aim to review previous literature and discuss the possible mechanisms of VA in TTC patients.

VA usually complicates the acute phase of the disease and worsens the long-term prognosis. Alterations of repolarization (negative T wave, prolonged QTc) indicate a high risk of arrhythmic events (TdP, VT, VF, and SCD). Catecholamine effect on myocardial cells and myocardial edema can create a substrate for the development of VA. Some of the most commonly proposed mechanisms for the development of VA in patients with TTC are coronary vasospasm, myocardial stunning due to catecholamines, re-entry, and triggered activity. Further prospective studies, including a more significant number of patients, are required to understand the disease's pathophysiology better and improve LTA management in patients with TTC.