Cardiology Letters 2026, 35(1):23-32

Long COVID and the pathophysiological mechanisms of cardiovascular damage

Angelika Púzserová¹, Peter Bališ¹, Silvia Dobrodenková², Enikő Potocká³, Miroslava Kvandová¹

¹ Ústav normálnej a patologickej fyziológie, Centrum experimentálnej medicíny, Slovenská akadémia vied, v. v. i., Bratislava, Slovakia

² Travel Health Clinic, Bratislava, Slovakia

Since 2019, SARS-CoV-2 infection has caused significant global morbidity and mortality. Following apparent recovery from acute COVID-19, many patients develop a chronic condition known as long COVID (LC), also referred to as post-COVID syndrome, which can persist for months to years, affect multiple organ systems, and represent a serious public health challenge. LC presents with highly heterogeneous symptoms and is diagnosed clinically due to the absence of specific biomarkers. The underlying pathophysiology is complex and incompletely understood, involving multiple mechanisms including viral persistence, immune dysregulation, microthrombus formation, endothelial dysfunction, and gut dysbiosis. Cardiovascular damage related to LC may result both from the direct action of SARS-CoV-2 and from indirect mechanisms. Long COVID is now recognized as an organic post-acute infection syndrome characterized by demonstrable physiological disturbances, particularly endothelial dysfunction. Endothelial cells are crucial for maintaining vascular homeostasis and regulating blood flow, inflammation, and coagulation. SARS-CoV-2 disrupts these processes, causing inflammation, reduced tissue perfusion, hypercoagulability, and microthrombosis. Globally, tens of millions live with LC. Accurate diagnosis and management require validated biomarkers and systematic follow-up. Despite accumulating evidence of its biological basis, patients are often inappropriately referred to psychiatric care or receive inadequate medical attention. This insufficient approach may lead to reduced quality of life, progression of symptoms, and delays in necessary diagnostics and treatment.

Keywords: case report; COVID-19; endothelial dysfunction; long COVID; pathomechanisms; SARS-CoV-2

Published: January 1, 2026  Show citation