A complicated unclassified cardiomyopathy

Case presentation: A 23-year-old man with no previous medical history was transported to our hospital following an episode of cardiac arrest. In the pre-hospital setting, his management consisted of advanced cardiopulmonary resuscitation maneuvers, mechanical ventilation and successful electrical cardioversion, with an estimated no-flow period of 8 min and low-flow period of 11 min. In the emergency department, initial evaluation found an unresponsive patient presenting a Glasgow score of 6, but otherwise stable vital signs. Intubation and mechanical ventilation was pursued, with no circulatory support. The clinical exam did not reveal any obvious anomalies at the cardiopulmonary exami-nation, nor did it reveal signs suggestive of drug abuse in the patient. The ECG demonstrated normal sinus rhythm with narrow QRS complexes and T wave abnormalities in the precordial leads. He underwent further diagnostic testing. Urgent coronary angiography show-ed normal coronary arteries, while pulmonary angio-CT came back negative for pulmonary embolism. Head CT was non-contributive. Lab exams were in normal range, including a complete electrolyte panel and TSH. Seventy-two hours later, he was successfully waned off mechanical ventilation without any complications with the ECG tracings now demonstrating large QRS complexes with signs of ventricular preexcitation. An ETT was performed and demonstrated a normal size, diffusely hypokinetic LV and a LVEF of 47%, with numerous trabeculations and deep recesses suggestive of LV noncompaction at the level of the apical segment of the inferolateral wall. The patient underwent an electrophysiological study and successful ablation of a malignant right anterolateral accessory pathway, but with no inducible atrial fibrillation following the pro-vocation maneuvers performed during the procedure. At this point, our differential diagnosis included: (1) rapidly conducted atrial fibrillation over the accessory pathways degenerating in ventricular fibrillation, (2) pulseless atrioventricular reentrant tachycardia in a patient with structural heart disease and (3) VT/VF in the context of an underlying structural cardiomyopathy. Because the echocardiographical findings were considered indeterminate in this young patient of African descent, we further explored his possible cardiomyopathy with a gadolinium enhanced cardiac MRI. The latter found a moderately hypertrophied, non-dilated LV, with a maximal wall thickness of 13mm at the level of the lateral wall and mild LV systolic dysfunction with a LVEF of 37%. Abnormal papillary muscle hyper-trophy was also noted. Formal CMR criteria for LVNC or other types of structural cardiomyopathy were not met and no pathological late-gadolinium enhancement was observed.
Conclusions: Considering his underlying unclassified cardiomyopathy complicated by LV systolic dysfunction, he underwent implantation of a subcutaneous cardioverter-defibrillator in secondary prevention of sudden cardiac death. Disease modifying therapy with ACE inhibitors and beta-blockers was initiated. Family history was a priori negative for sudden cardiac death or heart disease and no prior significant toxic expo-sure was identified. Genetic consultation and testing were performed and family screening was initiated. At 1-month follow up, he was doing well, resumed his favorite activities – playing boules, with no VT/VF recurrence.

ISSN – online: 2734 – 6382
ISSN-L 1220-658X
ISSN – print: 1220-658X
The Romanian Journal of Cardiology is indexed by:
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CODE: 379
CME Credits: 10 (Romanian College of Physicians)
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