CARDIAC ARRHYTHMIAS

With few exceptions, the etiologies of cardiac arrhythmias like those of bradycardia can best be recalled using the mnemonic VINDICATE. The exceptions are from one pathophysiologic cause: obstruction and consequent dilatation of one or more of the chambers of the heart. Thus, mitral stenosis with obstruction and dilatation of the left atrium is a prominent cause of atrial arrhythmias, especially auricular fibrillation. Hypertension and aortic stenosis may cause a number of atrial and ventricular arrhythmias. Pulmonary hypertension resulting from pulmonary emphysema, fibrosis, or pneumonia with consequent right ventricular and atrial obstruction, and dilatation cause arrhythmias, especially atrial arrhythmias.

CARDIAC ARRHYTHMIAS, LOCAL CAUSES

CARDIAC ARRHYTHMIAS, SYSTEMIC CAUSES

Getting back to VINDICATE completes the recall of the causes of arrhythmias.

1. V—Vascular diseases include myocardial infarction, coronary insufficiency, and coronary artery emboli.
2. I—Inflammatory diseases include viral myocarditis, diphtheria, syphilis, tuberculosis, and Chagas disease.
3. N—Neoplasms include atrial myxomas, but the N also stands for neuropsychiatric causes. Paroxysmal atrial tachycardia is especially likely to result from emotional causes.
4. D—Degenerative diseases include Friedreich ataxia, myotonic dystrophy, myocardial fibroelastosis, and other myocardopathies.
5. I—Intoxication suggests the largest number of causes of arrhythmia: Alcohol, caffeine, tobacco, digitalis, quinidine, propranolol, and procainamide are just a few. Diuretics cause electrolyte disturbances that may cause or contribute to cardiac arrhythmias.
6. C—Congenital disorders recall congenital heart diseases, many of which cause recurrent arrhythmias. The Wolff–Parkinson–White syndrome predisposes to atrial tachycardia. Muscular dystrophy may cause myocardiopathy and arrhythmias. Von Gierke disease and gargoylism also need to be remembered.
7. A—Autoimmune disorders suggest the arrhythmias of amyloidosis, sarcoidosis, scleroderma, periarteritis nodosa, and rheumatic fever,
8. T—Trauma suggests the arrhythmias in shock, burns, stab wounds to the heart, and head injuries. Electric shock is a cause of ventricular fibrillation.
9. E—Endocrinopathies should remind one of hyperthyroidism, a prominent cause of atrial fibrillation, Addison disease, and aldosteronism, which disturb the electrolytes sufficiently to cause arrhythmias. Pheochromocytomas may cause atrial tachycardia from the tremendous output of epinephrine.

Approach to the Diagnosis

The diagnosis depends a lot on the type of arrhythmia. Atrial premature contractions are usually benign and an extensive workup is unnecessary unless other physical signs indicate the need for it. Infrequent ventricular premature contractions (VPCs) in otherwise healthy individuals probably can be handled the same way. When VPCs are frequent or multifocal, an exercise tolerance test, echocardiogram, and perhaps coronary angiography are indicated. Runs of ventricular tachycardia require an extensive workup, including coronary angiography, but usually there will be other signs to indicate the need for this.

Atrial tachycardia and fibrillation require a workup of hyperthyroidism and pulmonary disease, systemic hypertension, and congestive heart failure. Atrial obstruction and dilatation should be excluded by echocardiography.

Any arrhythmia warrants an ECG and possibly repeated ECGs. The Holter monitor should be used if there is doubt about the type of arrhythmia.

Other Useful Tests

1. CBC (anemia)
2. Thyroid profile (hyperthyroidism, hypothyroidism)
3. Urinalysis (renal disease)
4. Chemistry panel (uremia, electrolyte imbalance)
5. Sedimentation rate (infection)
6. Serial cardiac enzymes (myocardial infarct)
7. Serum and urine osmolality (CHF)
8. Exercise tolerance test (coronary insufficiency)
9. Serial ECGs (myocardial infarct)
10. Signal-averaging ECG and electrophysiologic testing (localize site of irritable focus)
11. Pulmonary function tests (CHF, emphysema)
12. Echocardiogram (CHF, valvular heart disease)
13. Coronary angiogram (coronary insufficiency)
14. Drug screen (chronic drug abuse)
15. Hold all drugs (drug intoxication)

Book Source Details

• Book Title: Differential Diagnosis in Primary Care
• Author(s): R. Douglas Collins
• Year of Publication: 2007
• Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2007 Lippincott Williams & Wilkins.

Other Book Chapters Related to Arrhythmia

Read excerpts from these other book chapters related to Arrhythmia:

Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2008 Williams & Wilkins.

More About Causes of Arrhythmia

• Back to symptom: Arrhythmia: Introduction (review 234 causes)
• Next Book Extract About Arrhythmia: PALPITATION (Differential Diagnosis in Primary Care)
• All Book Extracts: All Online Book Extracts for Arrhythmia

More About This Book: Title: Differential Diagnosis in Primary Care Authors: R. Douglas Collins Publisher: Lippincott Williams & Wilkins Copyright: 2007 ISBN: 0-7817-6812-8

 » Next page: PALPITATION (Differential Diagnosis in Primary Care)

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• PALPITATION (Differential Diagnosis in Primary Care)
• Bradycardia (Handbook of Signs & Symptoms (Third Edition))
• Murmurs (Handbook of Signs & Symptoms (Third Edition))
• Palpitations (Handbook of Signs & Symptoms (Third Edition))
• Pulse rhythm abnormality (Handbook of Signs & Symptoms (Third Edition))

Tools & Services:

• Bookmark this page
• Related medical articles for Arrhythmias:
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City