A case report of percutaneous intramyocardial septal radiofrequency ablation in an adult with re-obstruction after Morrow procedure

Background

Some patients with hypertrophic cardiomyopathy (HCM) re-occur with drug-refractory symptoms but are not eligible for re-operation after the Morrow procedure. Traditional treatment options are limited. We present the first case of the use of ultrasound-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) for the treatment of a patient with HCM combined with congenital anatomically corrected malposition of the great arteries (MGA) after Morrow procedure.

Case summary

A 61-year-old male patient with congenital MGA, who had been treated with the Morrow procedure for HCM, had worsening symptoms in recent years that were difficult to control medically. He was diagnosed with occult obstructive HCM by stress echocardiography. After multi-disciplinary discussion, this patient was treated with PIMSRA. The post-operative clinical outcome was remarkable, with a significant decrease in septal thickness and disappearance of the left anterior branch conduction block.

Conclusion

Percutaneous intramyocardial septal radiofrequency ablation is feasible and can be one of the options for the treatment of patients with HCM, especially those who cannot choose Morrow procedure. However, it still needs a large sample of clinical trials to validate its clinical effectiveness.

Life-threatening ventricular arrhythmia and left ventricular dysfunction associated with anti-mitochondrial antibody-positive myositis: a case report

BACKGROUND

Anti-mitochondrial antibody (AMA)-positive myositis is an atypical inflammatory myopathy characterized by chronic progression of muscle atrophy and cardiac involvement. Few detailed reports have shown the clinical course of the cardiac complications of AMA-positive myositis.

CASE SUMMARY

A 47-year-old man presented with shortness of breath on exertion. Cardiac dilatation was visible on chest X-ray, and echocardiography demonstrated diffuse hypokinesis with a reduced left ventricular (LV) ejection fraction of 30%. He had mild muscle weakness in the bilateral iliopsoas muscles, and his creatine kinase (CK) and anti-mitochondrial M2 antibody levels were elevated. A liver biopsy showed no findings of primary biliary cholangitis. Coronary angiography revealed normal coronary arteries. An endomyocardial biopsy showed interstitial fibrosis and marked degeneration of the mitochondria. Fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography showed circumferential abnormal accumulation in the LV myocardium, and he was diagnosed with cardiomyopathy associated with AMA-positive myositis. Optimal drug therapy for heart failure was started, and a cardiac resynchronization therapy-defibrillator was implanted. However, his cardiac function did not improve, and he was hospitalized due to ventricular tachycardia storm 5 years after the diagnosis. Ventricular tachycardia was terminated by radiofrequency catheter ablation on the LV-anterior papillary muscle. Steroid therapy was initiated and resulted in a decreased uptake of FDG and a normalized CK level at 3 months after his second discharge; however, LV systolic dysfunction remained 1 year later.

DISCUSSION

Anti-mitochondrial antibody-positive myositis can affect the myocardium and cause severe LV dysfunction and life-threatening ventricular arrhythmia over time.

KEYWORDS

Anti-mitochondrial antibody-positive myositis • Endomyocardial biopsy • Ventricular tachycardia • Left ventricular dysfunction • Case report • Magnetic resonance imaging • Near-infrared spectroscopy-intravascular ultrasound.