Among ischemic heart disease (IHD) and its various manifestations, in recent years, according to different authors, the phenomenon of slow coronary flow, encountered in 1–5% of cases during angiographic examinations, remains a problematic condition faced by practicing cardiologists.

In patients with angiographically detected slow coronary flow, we investigated what role diastolic dysfunction, reduction of myocardial elasticity, and impaired filling of the heart with blood play.

Slow coronary flow was especially observed in patients with type III diastolic dysfunction – restrictive diastolic dysfunction.

The study included 75 patients aged 35–65 years (45 men and 30 women) with angiographically detected slow coronary flow.

In all patients, diastolic function indicators were measured: left atrial diastolic volume index (normal – 34 ml/m²), transmitral blood flow velocity (normal >2.8 m/s), E/e’ ratio (normal >14).

In 70% of the 75 examined patients, especially in those with signs of left ventricular hypertrophy, diastolic dysfunction was identified.

It is known that myocardial filling with blood occurs particularly during diastole. Thus, during diastole, the decrease of intramyocardial tension leads to sufficient filling of coronary vessels with blood. Ejection of blood, however, occurs during systole.

A decrease in myocardial elasticity and weakening of diastolic filling may lead to a reduction of filling of the cardiac chambers with blood and, as a mechanical factor, to increased resistance in the coronary vessels, causing a weakening of blood flow.

Thus, severe diastolic dysfunction, even without structural changes in the coronary arteries, can be one of the pathogenetic factors leading to impairment of their function, especially in the microcirculatory bed, and to disturbance of coronary flow.