Left ventricular dysfunction due to diffuse multiple vessel coronary artery spasm can be concealed in dilated...

Area of Science:

• Cardiology
• Cardiovascular Research
• Medical Diagnostics

Background:

• Idiopathic dilated cardiomyopathy (DCM) is often diagnosed by excluding coronary artery disease and identifying left ventricular (LV) dysfunction.
• Coronary artery multispasm is investigated as a potential cause of DCM-like LV dysfunction.

Purpose of the Study:

• To investigate coronary multispasm as a cause of idiopathic DCM.
• To assess the efficacy of calcium channel blockers in patients with LV dysfunction due to coronary multispasm.

Main Methods:

• Forty-two patients with LV dysfunction and no significant coronary stenosis underwent acetylcholine (ACh) provocation testing during coronary angiography.
• Patients were categorized based on ACh test results (positive or negative).
• Left ventricular function, MRI, and LV biopsies were assessed. Treatment response to calcium channel blockers was evaluated in the positive group.

Main Results:

• Twenty patients (48%) had a positive ACh test, showing multivessel coronary spasm and ECG changes.
• Patients with a negative ACh test more frequently showed idiopathic DCM findings on MRI (73%) and LV biopsy (71%).
• In the ACh-positive group, LV ejection fraction improved significantly (34% to 54%) after calcium channel blocker treatment, with reduced brain natriuretic peptide levels.

Conclusions:

• Coronary multispasm may be misdiagnosed as idiopathic DCM.
• Acetylcholine provocation testing can identify patients with coronary multispasm.
• Calcium channel blockers represent a potential therapeutic strategy for these patients.