Left ventricular apical diseases

Acute Coronary Syndrome Mimicking Takotsubo Cardiomyopathy or Takotsubo Cardiomyopathy Mimicking Acute Coronary Syndrome?

A healthy 66-year-old female presented to the emergency department with acute chest pain, T-wave inversion in the anterior leads, and elevated troponin-I. Coronary angiography showed a stenosis in the midportion of the left anterior descending coronary artery (LAD), which did not wrap the left ventricle (LV) apex. LV angiography demonstrated a large LV apical akinetic systolic ballooning with a 45% ejection fraction. Fractional flow reserve (FFR) of LAD lesion was 0.71. Percutaneous intervention was performed. At six months, transthoracic echocardiography was normal. Fifteen months later, the patient presented with chest pain and a small rise in troponin-I. Coronary angiogram was unchanged. Repeat FFR in distal LAD was 0.86 and left ventriculography was normal. Diagnostic criteria for Takotsubo cardiomyopathy (TTC) require the absence of obstructive coronary artery disease. In the present case, TTC was highly suspected on the basis of typical LV apex ballooning. However, significant ischemia in the same territory was demonstrated by positive FFR, which could not be falsely positive in this context. Current TTC diagnostic criteria increase specificity for diagnosing TTC. This case reminds us that it is at the price of reduced sensitivity, since there is no reason to believe that coronary lesions may protect from TTC.

Assessment of Left Ventricular Myocardial Diseases with Cardiac Computed Tomography

Rapid advances in cardiac computed tomography (CT) have enabled the characterization of left ventricular (LV) myocardial diseases based on LV anatomical morphology, function, density, and enhancement pattern. Global LV function and regional wall motion can be evaluated using multi-phasic cine CT images. CT myocardial perfusion imaging facilitates the identification of hemodynamically significant coronary artery disease. CT delayed-enhancement imaging is used to detect myocardial scar in myocardial infarction and to measure the extracellular volume fraction in non-ischemic cardiomyopathy. Multi-energy cardiac CT allows the mapping of iodine distribution in the myocardium. This review summarizes the current techniques of cardiac CT for LV myocardial assessment, highlights the key findings in various myocardial diseases, and presents future applications to complement echocardiography and cardiovascular magnetic resonance.

TakoTsubo cardiomyopathy: unravelling the malignant consequences of a benign disease with cardiac magnetic resonance

TakoTsubo cardiomyopathy (TCM) is a unique type of reversible cardiomyopathy that is precipitated by a stressful emotional or physical event. The increasing incidence is due to the greater use of emergency coronary angiography, newer cardiac biomarkers together with more sensitive cardiac imaging techniques. Few case reports have documented how TCM can present with malignant arrhythmias such as torsades de pointes caused by the repolarisation abnormalities or QTc prolongation. Although TCM is usually considered a benign reversible condition, its associated arrhythmic risk is increasingly recognised. TCM often presents as an acute coronary syndrome with unobstructed coronary arteries at angiography. In this patient population, cardiac magnetic resonance (CMR) is a useful tool to establish a differential diagnosis, discriminating TCM from acute myocarditis and myocardial infarction with spontaneous recanalisation. CMR is becoming a promising new diagnostic modality in risk stratifying patients with potential higher arrhythmic risk.