Clinical manifestations

Ischaemic symptoms

This group of presenting symptoms includes angina, acute coronary syndrome and myocardial infarction.

Coronary ischaemia is a result of an imbalance between supply and demand. In the general population, this is largely determined by either occlusion or narrowing of the coronary vessels, but in the renal population other factors are important. These include:

		excess of left ventricular hypertrophy, increasing the burden;
		decreased oxygen delivery due to anaemia; and
		abnormal cellular energetics, possibly related to abnormalities of calcium metabolism.

There are also observational data showing increased coronary artery calcification in young dialysis patients, but the pathological significance of this is unclear. Moreover, small-vessel disease in diabetics is common by the time such patients are on dialysis.

The rates of ischaemic symptoms, including myocardial infarction are increased in patients with end-stage renal failure.

Arrhythmias

Many arrhythmias may be seen in dialysis patients both during, and between, dialysis.

These can be related to abnormalities of the conduction system through calcification and ischaemia or may be mediated by changes in the haemodynamics or metabolic milieu during dialysis.

Atrial fibrillation is particularly common, and may be either paroxysmal or persistent.

Left-ventricular hypertrophy

This is an almost universal finding in patients on dialysis. The process is probably an adaptive one to anaemia and hypertension which has become maladaptive, with a high associated mortality rate owing to heart failure and acute coronary events.

Pericardial disease

Pericardial disease may reflect under dialysis or infection, such as tuberculosis

Valvular disease

Valvular disease may be divided into valvular calcification and endocarditis.

Infective endocarditis is an important complication within the dialysis population, occurring in one to five percent of patients on haemodialysis.

It is more common in patients who are dialysing through long-term cuffed subcutaneous venous catheters and with PTFE grafts. However, a major predisposing factor is valvular calcification.

Abnormalities of valve function are also relatively common, with increased rates of calcifications of both aortic and mitral valves, resulting in stenosis. In addition, there is a high prevalence of mitral, aortic and tricuspid regurgitation. Much of the aetiology of this is related to poor volume control, so correction of volume may result in regression of these functional regurgitant lesions.