Normal Variants and Pitfalls in Cardiac PET/CT

A review of cardio-pulmonary microvascular dysfunction in pulmonary hypertension

Microvascular dysfunction progressing to pulmonary hypertension can be a primary cause of right ventricular failure or a secondary cause because of an underlying systemic illness. Little is known regarding the etiology and epidemiology of coronary microvascular dysfunction in pulmonary hypertension. Despite this limitation, its presence has been described in patients with pulmonary hypertension. This review focuses on the pathogenesis of cardiac and pulmonary microvascular dysfunction in pulmonary hypertension. Additionally, this review provides a contemporary assessment on the diagnosis and treatment of microvascular dysfunction in patients in pulmonary hypertension. This topic is important to raise awareness of microvascular dysfunction in the coronary and pulmonary circulation, so that future studies will investigate its impact on the pulmonary hypertension patient cohort.

Novel nuclear medical procedures in the detection of microvascular dysfunction

Coronary microvascular dysfunction is present in two-thirds of patients showing symptoms and signs of myocardial ischemia. Their microcirculation has abnormalities due to endothelial and smooth muscle cell dysfunction. Impairment of this mechanism causes a high risk of adverse cardiovascular event. Diagnosing coronary microvascular dysfunction is challenging. Guidelines recommend the use of nuclear medicine procedures in the above-mentioned indications. Myocardial perfusion imaging with positron emission tomography is a novel procedure with high diagnostic accuracy and quality of images. It has short acquisition, low effective radiation dose and prognostic factors. There are still unknowns about this procedure and all its benefits.