Shortness of breath (dyspnea) can result from lung disease or simply from being out of shape. But shortness of breath can also be a significant risk factor for death from cardiac causes.
A recent study followed nearly 18,000 patients for an average of 2.7 years after undergoing a CT scan of their heart. The death rate from cardiac causes and from any cause was significantly greater among patients who reported they had dyspnea than among those who did not report dyspnea. This increased risk was present whether they were previously known to have coronary heart disease or not.
Among patients with no known coronary disease, the risk of sudden death from cardiac causes was 4 times greater in those with shortness of breath compared to those without any symptoms. In addition, the risk of sudden cardiac death was twice as great in patients with dyspnea than in those with chest pain typical of angina. Shortness of breath significantly raised the risk of death from cardiac causes or from any cause even after adjustments for other important risk factors.
The authors of the study had no explanation for the relationship between shortness of breath and cardiac deaths. Prior heart damage that impaired the pumping function of the left ventricle seemed a logical cause, but their assessments did not find any abnormality of left ventricular function.
Be sure to notify your physician if you experience shortness of breath so this symptom can be added to other factors when decisions are made whether or not to carry out tests on your heart.