Cardiac imaging is essential for demonstrating abnormal cardiac function and thus, making a diagnosis of heart failure. Imaging can detect complications of heart failure, such as left ventricular thrombus, and provides an objective measure of deterioration which may influence treatment.
Echocardiography is the most commonly used imaging investigation. It is widely available, portable and relatively cheap. The combination of M-mode, 2D, spectral Doppler and colour Doppler echocardiography can provide a wealth of information on cardiac structure and function.
Echocardiography allows accurate measurement of:
- LV end-diastolic and end-systolic dimensions – often increased in heart failure (figure 6)
- LV end-diastolic and end-systolic volumes – for estimation of ejection fraction
- left atrial (LA) size/volume – often increased in heart failure: LA size indexed for body surface area is a diagnostic criterion for HeFNEF
- mitral valve structure – often systolic tenting or restricted posterior leaflet in ischaemic cardiomyopathy (figure 7)
- aortic, pulmonary and tricuspid valve structure
- size of pleural +/- pericardial effusions
- size and collapsibility of the inferior vena cava (IVC) – rarely entirely normal in heart failure; this gives a useful non-invasive indication of right atrial pressures (figure 8)
- complications of cardiac dysfunction – e.g. intra-cardiac thrombus (figure 9).