As a cardiologist, there is no enough proof or evidence to support the idea that left side sleeping can increase your risk of heart attacks or disorders especially in individuals with a healthy heart. The only known risks of sleeping on the left side might be experienced in people with prevailing heart disorders and might include pain, changes in ECG activity as the electrical currents or signals are interrupted, difficulty breathing, and discomfort. Left side sleeping can trigger alterations or shifting of the heart movements but has not shown to heighten risks of heart attacks.
There are no other sleeping positions that are associated with heart attack risks though right side sleeping can exert pressure on the vena cava causing discomfort.
