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How to standardize vasomotor tone in serial studies based on quantitation of coronary dimensions?
Insights
Standardizing coronary artery tone in angiography is crucial. Nitroglycerin, administered repeatedly, offers the most effective and reproducible maximal coronary dilation for serial studies in patients with coronary artery disease.
Area of Science:
- Cardiology and Interventional Radiology
- Pharmacology of Cardiovascular Drugs
Background:
- Serial quantitative coronary angiography is vital for studying coronary artery disease, including post-coronary bypass graft and heart transplant patients.
- Standardizing coronary tone via maximal dilation is essential for accurate angiographic follow-up studies due to influences on vasomotor tone.
Purpose of the Study:
- To review the effects of potent coronary vasodilatory drug classes, calcium antagonists and nitrocompounds, on coronary diameters.
- To identify optimal drug regimens for standardizing coronary vasomotor tone in serial angiographic studies.
Main Methods:
- Review of existing literature on the effects of calcium antagonists (verapamil, diltiazem, nifedipine, nicardipine, nisoldipine) and nitrocompounds (isosorbide dinitrate, molsidomine, SIN-1, nitroglycerin) on coronary diameters.
- Analysis of drug administration routes (intravenous, intracoronary, sublingual), onset of action, duration, efficacy, and side effects.
Main Results:
- Calcium antagonists like verapamil and nisoldipine induce maximal coronary dilation but have limitations such as short duration and blood pressure effects.
- Isosorbide dinitrate causes dilation but with potential blood pressure decrease; molsidomine/SIN-1 offer long-lasting dilation but with a delay and limited availability.
- Nitroglycerin provides reproducible maximal coronary dilation with rapid onset and minimal side effects, with repeated intracoronary injections (0.1 mg every 10 minutes) being the optimal regimen identified.
Conclusions:
- Nitroglycerin is the preferred agent for standardizing coronary vasomotor tone in serial angiographic studies due to its efficacy, safety, and administration ease.
- Further research into both existing and novel vasodilatory drugs is recommended for optimizing coronary tone standardization in cardiovascular imaging.
Abstract:
In patients with coronary artery disease including those after coronary bypass graft operation and heart transplantation intervention studies based on serial quantitative coronary angiography, in part combined with intravascular ultrasound, are of increasing relevance. Since vasomotor tone of epicardial coronary arteries is influenced by a variety of factors, angiographic follow-up studies require standardization of coronary tone by induction of maximal dilation. We reviewed the effects of the most potent coronary vasodilatory drug groups, calcium antagonists and nitrocompounds, on coronary diameters. Intravenous or intracoronary injections of verapamil, diltiazem, nifedipine, nicardipine, and nisoldipine can cause profound coronary dilation which has been shown to be maximal with verapamil and nisoldipine. Shortcomings of calcium antagonists include short or unknown duration of action after bolus administration, severe drop in blood pressure, and lack of commercial availability of solutions for injection of many substances. Isosorbide dinitrate induces profound coronary dilation; however, after sublingual administration marked blood pressure decrease can occur, and the duration of action and ideal dose of intracoronary isosorbide dinitrate has not been investigated yet. Injections of molsidomine and its active metabolite, SIN-1, cause longlasting, reproducible, maximal coronary dilation, although only after a waiting period of at least 10 minutes; unfortunately, SIN-1 is only commercially available in France. Nitroglycerin induces reproducible maximal coronary dilation and is easy to administer sublingually or as intracoronary bolus injection with rapid onset of action and no major side effects. The short duration of action may require repeated administrations. To date, repeated intracoronary bolus injections of 0.1 mg nitroglycerin every 10 minutes seem to be the optimal known regimen for standardization of coronary vasomotor tone in serial angiographic studies. Further investigations in this field with old and new vasodilatory drugs are recommendable.