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Basics ⬇

Basics

Overview

  • Atrialization of the right ventricle-an apical displacement of the tricuspid valve complex into the right ventricle.
  • Accompanied by various degrees of tricuspid insufficiency or stenosis.
  • Major pathophysiology related to the degree of tricuspid insufficiency or stenosis.
  • An abnormal accessory pathway may lead to supraventricular tachycardias.

Signalment

  • Very rare-occasionally encountered in dogs and cats.
  • No breed or sex predilection.
  • Murmur auscultated at a young age, though can be very difficult to auscult with stenosis.

Signs

  • Animals with mild tricuspid insufficiency or stenosis are asymptomatic.
  • Animals with moderate insufficiency or stenosis are often exercise intolerant.
  • Animals with severe insufficiency or stenosis have R-CHF with pleural effusion and/or ascites.

Diagnosis ⬆ ⬇

Diagnosis

Differential Diagnosis

Tricuspid dysplasia

CBC/Biochemistry/Urinalysis

Results usually normal

Other Laboratory Tests

N/A

Imaging

Thoracic Radiography

  • Right atrial and ventricular enlargement
  • Hepatomegaly

Echocardiography

  • Two-dimensional echocardiography reveals an apically displaced tricuspid valve with an enlarged right atrium and small right ventricle.
  • Color Doppler shows tricuspid insufficiency and/or tricuspid stenosis.
  • Spectral Doppler confirms tricuspid stenosis and estimates right ventricular pressure.

Other Diagnostic Procedures

Electrocardiography

  • Simultaneous intracardiac pressure and ECG tracings may be needed to verify the diagnosis.
  • Accessory conduction pathway (ventricular preexcitation) or supraventricular tachycardia.

Treatment ⬆ ⬇

Treatment

Medications ⬆ ⬇

Medications

Drug(s)

  • Patients with R-CHF-start furosemide (2–4 mg/kg q6–12h) and enalapril (0.5 mg/kg q12h).
  • Patients with tricuspid stenosis-gradually increase atenolol dose (0.1–1 mg/kg q12h) to obtain low normal heart rate to facilitate ventricular filling.
  • Patients with supraventricular tachycardia (WPW syndrome)-start procainamide (15 mg/kg q8h).
  • If WPW syndrome persists, consider a calcium channel blocker (i.e., verapamil or diltiazem) or a beta-blocker (e.g., propranolol or atenolol).

Contraindications/Possible Interactions

Do not use calcium channel blockers and beta-blockers concurrently

Follow-Up ⬆ ⬇

Follow-Up

Monitor with serial echocardiography

Miscellaneous ⬆

Miscellaneous

Abbreviations

  • ECG = electrocardiography
  • R-CHF = right-sided congestive heart failure
  • WPW = Wolff-Parkinson-White (syndrome)

Author Jean M. Betkowski

Consulting Editors Larry P. Tilley and Francis W.K. Smith, Jr.

Acknowledgment The author and editors acknowledge the prior contribution of Carroll Loyler.

Suggested Reading

Bonagura JD, Lehmkuhl LB. Congenital heart disease. In: Fox PR, Sisson D, Moise NS, eds., Textbook of Canine and Feline Cardiology. 2nd ed.Philadelphia: Saunders, 1999, pp. 471–535.

Webb GD, Smallhorn JF, Therrien J, Redington AN. Congenital heart disease. In: Bonow RO, Mann DC, Zipes DP, Libby P, eds., Braunwald's Heart Disease. 9th ed.Philadelphia: Elsevier Saunders, 2012, pp. 1450–1452.