The diagnostic role of cardiac magnetic resonance used “first and last time in life” in a patient with a suspected dilated phase of hypertrophic cardiomyopathy

Case report

A 38-year-old female patient with neither diagnosis nor family history of any heart disease was admitted to the regional hospital with sustained ventricular tachycardia (220 bpm). Tachyarrhythmia was successfully treated with intravenous amiodarone. Total time of sustained ventricular tachycardia was no more than 1 h (from the start of symptoms at home to the end of arrhythmia in the emergency department in a regional hospital). The pulmonary congestion was revealed both in physical and X-ray examination. Extremely high levels of high-sensitivity troponin I (> 40 000 ng/l) as well as NT-proBNP (21 055 pg/ml) were detected. In control sampling after several days the level of troponin I was still very high: 39 185 ng/l. The patient was transferred to our tertiary center where in the face of a prolonged period of an extremely high level of troponin I, the decision to perform coronary angiography was made. The coronary artery angiogram was normal. Echocardiography revealed myocardial hypertrophy and mild dilatation of the left ventricle (LV). The LV ejection fraction (EF) was low, i.e. 28%. The suspicion of the starting phase of the dilative stage (burn-out) of hypertrophic cardiomyopathy (HCM) was suggested and cardiac magnetic resonance (CMR) imaging with gadolinium contrast was proposed to explore the hypothesis.
The CMR confirmed myocardial hypertrophy distributed in several segments. Maximal thickness of the myocardium was 19 mm in diastole. Total LV mass was increased to 303 g (156 g/m2).
Mild LV cavity dilatation was characterized by the following parameters: end diastolic volume of 318 ml (163 ml/m2) and end systolic volume of 271 ml (112 ml/m2). Low EF was confirmed at the level of 30%. A large amount (29.6%) of late gadolinium enhancement (LGE) with a diffused pattern was noted (Figure 1).
An episode of sustained ventricular tachycardia has been recognized as a major risk factor of sudden cardiac death (SCD). Therefore, an implantable cardioverter-defibrillator with resynchronization (R-ICD) was implanted. This decision was supported by a wide QRS (130 ms) complex and NYHA class defined as III during hospitalization. Resynchronization was introduced due to low LV EF. The decision of electrotherapy as secondary prevention of SCD was supported by a massive amount of LGE representing the arrhythmia substrate. Unfortunately, R-ICD implantation will not allow follow-up examinations with CMR to be made in the future....


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