heart author" faq

Causes of Bradycardia Table

Intrinsic Causes

Idiopathic degeneration (aging)

Infarction or ischemia (heart attack or reduced coronary arterial blood flow)

Infiltrative diseases

Sarcoidosis: the development of granulomatous lesions (cause unknown) in the heart, bones, lungs, etc

Amyloidosis: deposition of a near transparent waxy material due to degeneration of body tissues in chronic disease (see figures 73a, 73b, 74, 76, 77).

Hemochromatosis: deposition of iron into tissue

Collagen vascular disease (arteritis, periarteritis nodosa, etc.)

Systemic lupus erythematosis: chronic disease involving multiple organs like the skin, connective tissue, kidneys, spleen, heart, gastro intestinal tract, etc.

Rheumatoid arthritis: chronic inflammation of the joints and some organs, of unknown cause, possibly related to abnormal immune mechanisms.

Scleraderma: chronic inflammatory process causing severe increase in connective tissue in organs, skin, etc., cause unknown.

Myotonic muscular dystrophy (abnormal, inherited disease of muscles, with faulty development of degeneration of muscles)

Surgical trauma

Valve replacement

Correction of congenital heart disease

Heart transplantation

Familial diseases (inherited)

Infectious diseases

Chagas' disease: a chronic wasting disease caused by a parasite (Trypanosoma Cruzi), prevalent in Central and South America.

Endocarditus: secondary to dental procedures causing infection in the blood stream, illicit drug injections into veins, etc.


Extrinsic Causes

Autonomically mediated syndromes (i.e. vomiting, sleeping, etc.)

Neurocardiac syncope

Carotid-sinus hypersensitivity: from vagus innervation hypertonicity

Situational disturbances: coughing, micturition, defecation, vomiting


B-Adrenergic blockers: inderal, atenolol, etc.

Calcium-channel blockers: procardia, verapamil, diliatezern

Clonidine: for hypertension

Digoxin: for heart failure, atrial fibrillation, etc.

Antiarrhythmic agents: pronestyl, quinidine, etc.

Hypothyroidism (abnormally low thyroid hormone in the blood stream)
Neurologic disorders (affecting autonomic nervous system)

Electrolyte imbalances

Hypokalemia: low potassium

Hyperkalemia: high potassium