Coronary microvascular disease in hypertensives

Area of Science:

• Cardiology
• Hypertension Research
• Vascular Biology

Background:

• Arterial hypertension affects coronary circulation via coronary artery disease, left ventricular hypertrophy, and microvascular disease.
• Coronary microvascular disease (CMD) in hypertensives may reduce coronary flow reserve and shift the autoregulation curve.
• Dipyridamole-echocardiography can detect microvascular dysfunction in conditions like Syndrome X and hypertrophic cardiomyopathy.

Purpose of the Study:

• To investigate the presence and consequences of coronary microvascular disease in patients with essential hypertension.
• To assess the utility of dipyridamole-echocardiography in identifying hypertensive patients with CMD.
• To explore the relationship between CMD, ventricular arrhythmias, and response to antihypertensive treatment.

Main Methods:

• Utilized dipyridamole-echocardiography to assess coronary circulation.
• Evaluated mild-moderate essential hypertensives with normal epicardial arteries and increased forearm vascular resistance.
• Monitored for echocardiographically silent ST segment depression, a marker of ischemic-like response.

Main Results:

• Dipyridamole infusion induced ST segment depression in hypertensives, indicating CMD despite normal epicardial arteries.
• This response was associated with reduced coronary reserve and increased risk of ventricular arrhythmias.
• The observed microvascular dysfunction and forearm vascular resistance were reversible with chronic antihypertensive treatment.

Conclusions:

• Coronary microvascular disease is a significant complication in essential hypertension, affecting coronary flow reserve.
• Dipyridamole-echocardiography can identify this microvascular dysfunction in hypertensives.
• Chronic antihypertensive therapy can reverse CMD and reduce associated risks, including ventricular arrhythmias.