How does hypercalcemia affect the heart?

As a medical professional with expertise in cardiology, I can explain the effects of hypercalcemia on the heart. Hypercalcemia, which is a condition characterized by abnormally high levels of calcium in the blood, can have several significant impacts on cardiac function. Firstly, elevated calcium levels can lead to the formation of calcifications in the heart's blood vessels and valves, which can impair their function. This can result in conditions such as aortic stenosis or mitral valve disease. Secondly, hypercalcemia can cause arrhythmias, which are irregular heartbeats. High calcium levels can alter the electrical activity of the heart, leading to a disruption in the normal rhythm. Thirdly, the condition can lead to digitalis toxicity. Digitalis is a medication used to treat heart failure and certain types of irregular heartbeats. However, in the presence of hypercalcemia, the body's sensitivity to digitalis increases, which can lead to toxic effects. Lastly, hypercalcemia can cause decreased contractility of the heart. High levels of calcium can affect the heart muscle's ability to contract and pump blood effectively. In summary, hypercalcemia can affect the heart by causing calcifications, arrhythmias, digitalis toxicity, and decreased contractility, all of which can have serious health consequences.

Limbus sign seen in eye due to hypercalcemia. Hypercalcemia can result in an increase in heart rate and a positive inotropic effect (increase in contractility). Symptoms are more common at high calcium blood values (12.0 mg/dL or 3 mmol/l).