Dysautonomia: an overlooked primary etiology of unexplained cardiac manifestations

Background Dysautonomia refers to abnormal function of the autonomic nervous system leading to disordered control of cardiovascular, gastrointestinal, thermoregulatory, pupillary, genitourinary and other homeostatic processes. Dysautonomia frequently causes cardiac symptoms including palpitation, chest pain, and shortness of breath. It is not uncommon for patients to present with cardiac manifestations of dysautonomia (palpitations, dizziness, chest discomfort, fainting) while all standard investigations show non-significant abnormalities, including ECG, echocardiography, stress tests, Holter monitoring, multislice computed tomography coronary angiography (MSCT CA), and even invasive coronary angiography. Head-up tilt table testing (HUTTT) is crucial in this context because dysautonomia is a functional disorder, whereas standard cardiac tests are designed primarily to detect structural disease. Aim and Objectives To study the prevalence of chest pain, palpitation, and chest tightness among patients with documented neurocardiogenic disorders confirmed by tilt table testing. Methods One hundred and twenty-two patients with documented neurocardiogenic disorders by tilt table testing were retrospectively analyzed for their presenting complaints. The prevalence of cardiac complaints, including chest pain, chest tightness, and palpitation, was studied and statistically analyzed. Results Statistical analysis of the main complaints of the 122 enrolled dysautonomic patients revealed that cardiac complaints accounted for 32% (n = 39) of the total dysautonomic population diagnosed by positive HUTTT. Chest pain was the predominant complaint in 7.4% of patients (n = 9), palpitation in 12.3% (n = 15), and chest tightness in 12.3% (n = 15). Other non-cardiac complaints involved 68% of all dysautonomic patients (n = 90) and included drowsiness, abdominal pain, tinnitus, dysphagia, blurring of vision, and hoarseness of voice. Conclusions This study contributes to the growing body of evidence recognizing that dysautonomia and vagal dysfunction extend beyond classical syncope, with cardiac symptoms representing a significant clinical burden. The distinct autonomic response profiles associated with chest pain, palpitation, and chest tightness provide clinicians with valuable diagnostic clues and emphasize the importance of considering dysautonomia and vagal dysfunction in the differential diagnosis of unexplained cardiac symptoms. Early recognition of these non-syncope manifestations may lead to more timely diagnosis, appropriate management, and improved quality of life for affected patients.