Cario. Ventricular failure DCM Chap 40

Question 1

Definitions:

Heart failure:

Systolic heart failure:

Diastolic heart failure:

Congestive heart failure:

Forward heart failure:

Backward heart failure:

Circulatory failure:

Answer 1

Heart failure: The pathophysiologic state in which the heart is unable to pump sufficient blood to meet the metabolic demands while maintaining normal arterial and venous pressures.

Systolic heart failure: A defect in the pumping or contractile function of the heart.

Diastolic heart failure: A defect in the filling or relaxation function of the heart.

Congestive heart failure: The clinical syndrome that results when abnormal cardiac function causes accumulation and retention of fluid, resulting in signs of congestion and edema.

Forward heart failure: Decreased cardiac output results in inadequate delivery of blood to the arterial system, leading to diminished organ and muscle perfusion.

Backward heart failure: Elevated filling pressure causes increased pressure within the left atrium and the pulmonary vasculature draining into the left atrium. This results in elevated capillary hydrostatic pressure, transudation of fluid into the interstitium,
and pulmonary edema. If right-sided heart disease is present and right atrial pressure is increased, the same process can lead to elevated systemic venous pressure, ascites and subcutaneous edema

Circulatory failure: When the delivery of oxygenated blood is insufficient to meet the metabolic demands of the body tissue.

Question 2

Ventriculr failure can be primary, secondary or extracardia i.e.:

Answer 2

DCM, ARVC
secondary to advance MMVD, PDA
Adriamycin, sepsis (40% humans), malnutrition (taurine, L-carnitine, selenium), doxorunricin

Question 3

PE finding of ventricular failure:

Answer 3

• weak femoral pulse quality bc of decreased CO

- LV dilation worsens andresults in stretching of the mitral valve annulus, soft left apical murmur

Question 4

ECG findings:
ventricular hypertrophy:
left-sided heart disease:
right ventricular hypertrophy:

Answer 4

• QRS prolonged
• leads I, II, III and aVF tall R waves = increased LV mass

-QRS complex is likely to have late negative deflections in leads I, II, III, and aVF, consistent with a rightward-
shifted mean electrical axis

Question 5

normal VHS:
Dog:
Cat:

Answer 5

<10.7

<8

Question 6

Laplace’s law and how it relates to DCM:

Answer 6

Laplace’s law: wall stress = [pressure × radius] / 2 [wall thickness]

• as ventricle dilates, EDV and EDP increases = increases wall stress throughout the entire cardiac cycle
• any left ventricular size (radius), the greater the developed pressure, the greater the wall stress

.:. Increased wall stress caused by either of these mechanisms will increase the myocardial oxygen requirement and result in more myocardial energy