Atrioventricular dissociation due to pheochromocytoma in a young adult

Systemic Diseases and Heart Block

Systemic diseases can cause heart block owing to the involvement of the myocardium and thereby the conduction system. Younger patients (<60) with heart block should be evaluated for an underlying systemic disease. These disorders are classified into infiltrative, rheumatologic, endocrine, and hereditary neuromuscular degenerative diseases. Cardiac amyloidosis owing to amyloid fibrils and cardiac sarcoidosis owing to noncaseating granulomas can infiltrate the conduction system leading to heart block. Accelerated atherosclerosis, vasculitis, myocarditis, and interstitial inflammation contribute to heart block in rheumatologic disorders. Myotonic, Becker, and Duchenne muscular dystrophies are neuromuscular diseases involving the myocardium skeletal muscles and can cause heart block.

Systemic Diseases and Heart Block

Systemic diseases can cause heart block owing to the involvement of the myocardium and thereby the conduction system. Younger patients (<60) with heart block should be evaluated for an underlying systemic disease. These disorders are classified into infiltrative, rheumatologic, endocrine, and hereditary neuromuscular degenerative diseases. Cardiac amyloidosis owing to amyloid fibrils and cardiac sarcoidosis owing to noncaseating granulomas can infiltrate the conduction system leading to heart block. Accelerated atherosclerosis, vasculitis, myocarditis, and interstitial inflammation contribute to heart block in rheumatologic disorders. Myotonic, Becker, and Duchenne muscular dystrophies are neuromuscular diseases involving the myocardium skeletal muscles and can cause heart block.

Looking Deep Into the Palpitation - Pheochromocytoma Presenting as Sinus Node Dysfunction

A 23-year-old male came to the outpatient department with a history of intermittent palpitations and headaches for the past six to eight months. He was diagnosed with hypertension and had a junctional rhythm on an electrocardiogram (ECG). On further workup for his hypertension, he was found to have elevated levels of serum metanephrines and computed tomography (CT) and positron emission tomography (PET) scan revealed pheochromocytoma. He was subsequently operated upon and his arrhythmia subsided after surgery. We discuss our approach to this scenario, which leads us to a rather rare cause of sinus node dysfunction.

Complete atrioventricular dissociation and sinus arrest after pheochromocytoma resection

INTRODUCTION

Although preoperative bradycardia has been reported in several pheochromocytoma cases, postoperative bradycardia has not. This is the first case report of complete atrioventricular dissociation and sinus arrest occurring after pheochromocytoma resection.

CASE PRESENTATION

A 38-year-old woman was referred for a left adrenal incidentaloma. Twenty-four hour urinary collection showed elevated noradrenaline. Iodine-123-meta-iodobenzylguanidine scintigraphy showed high tracer uptake in the left adrenal region. Open left adrenalectomy was performed, and histopathological examination confirmed the diagnosis of pheochromocytoma. Thirty minutes following surgery, complete atrioventricular dissociation and sinus arrest developed. Vagal reflex attenuation due to decreased noradrenaline after tumor removal and perioperative pain and fear were believed to be the causes. A temporary pacemaker was implanted to prevent sudden death due to vagal overstimulation.

CONCLUSION

Vagal reflex attenuation after pheochromocytoma resection can result in complete atrioventricular dissociation and sinus arrest. Adequate preoperative preparation and close monitoring during and after surgery are imperative.

[Pathogenetic mechanisms of development of myocardial pathology in patients with malignant tumors: the current state of the problem]

The myocardium, which has a high metabolic activity, responds to metabolic disorders and energy imbalance induced by a growing malignant tumor. In addition, the tumor itself can produce substances that directly affect metabolic processes and the life cycle of cells not involved in the neoplastic process, including cardiomyocytes. This review summarized and systematized current data on individual aspects of detrimental effects of oncogenes and tumor-related factors on the heart muscle and morpho-functional changes in the cardiovascular system of oncology patients. Also, the authors described in detail development of these pathogenetic mechanisms.