Possible causes of symptoms in suspected coronary heart disease but normal angiograms

Background : In patients with suspected coronary heart disease and normal angiography, the causes of cardiac symptoms frequently remain undetermined. A correct diagnosis is desirable, however, since some of the underlying disorders may be curable, treatable, influence prognosis, or induce screening of the relatives. Hypothesis : In such patients, the prevalence of arterial hypertension, hemochromatosis, hypothyroidism, hypoparathyroidism, tachycardiomyopafhy, amyloidosis, and neuromuscular disorders as a possible cause for their symptoms and the seroprevalence of micro‐organisms, known to cause myocardial damage, were assessed. Methods : Consecutive patients with normal coronary angiograms were invited for two visits comprising clinical history and investigation, electrocardiograms, blood tests, and echocardiography. Patients were investigated neurologically if unexplained anginal chest pain or creatine kinase elevation persisted or if echocardiography showed isolated left ventricular abnormal trabeculations. Results : In 71 patients (31 women, 40 men, mean age 60 years), the most common cause for cardiac symptoms was hypertension (66%), followed by neuromuscular disorders (13%), tachycardiomyopathy (9%), hypothyroidism (4%), and hemochromatosis (3%). The seroprevalence for Chlamydia species was 90%, Helicobacter pylori 70%, Chlamydia pneumoniae 63%, Borrelia burgdorferi sensu lato 15%, and Rickettsia conorii 10%. No possible cause was found in 24% of the patients. Conclusions : In patients with suspected coronary heart disease and normal angiograms, hypertension, neuromuscular disorders, tachycardiomyopathy, hypothyroidism, and hemochromatosis should be considered as possible causes.