Patients with heart disease have some abnormality of cardiac form and/or mechanical or electrical function, whereas not all patients with heart disease have heart failure. Only those with advanced heart disease may experience heart failure.
Recall from the last course module on Physiology and Pathophysiology, heart failure was defined as an inability of the heart to meet the demands of the body and its tissues. A more specific subset of heart failure is congestive heart failure, which is characterized by abnormally increased preload (increased cardiac filling pressures) causing the accumulation of edema or effusions, the locations of which depend on the side(s) of the heart involved.
So the presence of heart disease may be detected by the presence of:
- a heart murmur
- other abnormal heart sound like a systolic click or a gallop
- an arrhythmia
- an abnormal heart rate
- weak femoral arterial pulses
- pulses deficits (accompanying an arrhythmia)
Note, however, that the absence of these findings does not rule out the presence of heart disease. There are a number of cardiac diseases that may result in normal physical examination findings. And note that not all of these findings are specific to cardiac disease. We learned that heart murmurs may be functional or present for physiologic reasons, arrhythmias may be secondary to many systemic diseases, and weak pulses may be related to hypovolemia, as examples.
Similarly there are no pathognomonic findings for heart failure; however, given our understanding that this stage of disease is characterized by increased preload, congestion, and potentially reduced cardiac output, findings could include some of the following in addition to those listed above:
- slow capillary refill time (> 2 sec)
- pale or cyanosed mucous membranes
- cool extremities or reduced rectal temperature
- jugular venous distention or positive hepatojugular reflux test
- tachypnea with or without dyspnea – this is an important one! – patients with left-sided heart failure (active pulmonary edema) have tachypnea, and if severe it is accompanied by dyspnea. Cough alone does not indicate heart failure.
- increased lung sounds, wheezes, or crackles on auscultation – remember again these findings are not specific to heart failure
- decreased lung sounds if pleural effusion
- increased heart rate – most patients in active congestive heart failure will be relatively tachycardic, unless the cause is or their disease is accompanied by a bradyarrhythmia
- hepatomegaly and/or splenomegaly from venous congestion secondary to right-sided heart failure
- abdominal effusion secondary to right-sided heart failure
- subcutaneous edema – this is quite rare in small animal heart disease