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[Anti-ischemic effect of verapamil within the scope of interventional recanalization]
O Oldenburg1, D Baumgart, J Schaar
1Abteilung für Kardiologie, Universitätsklinikum Essen. olaf.oldenburg@uni-essen.de
Insights
A patient with unstable angina experienced slow coronary blood flow after angioplasty and stenting. Verapamil administration improved flow and relieved ischemia, suggesting vasoconstriction mechanisms in coronary microcirculation.
Area of Science:
- Cardiology
- Interventional Cardiology
- Physiology
Background:
- Unstable angina pectoris (UAP) can result from complex coronary artery lesions.
- Percutaneous coronary intervention (PCI) with stenting is a common treatment for occlusive coronary artery disease.
Observation:
- A 46-year-old male with UAP presented with total proximal left circumflex artery occlusion.
- PCI and stenting led to a significant decrease in baseline coronary blood flow velocity, termed the "slow flow phenomenon."
- Despite reduced baseline velocity, coronary flow velocity reserve (CFVR) remained adequate.
Findings:
- Verapamil administration normalized baseline coronary blood flow velocity and improved electrocardiogram (ECG) signs of ischemia.
- Coronary blood flow velocity in the non-treated left anterior descending artery also increased post-verapamil.
- The slow flow phenomenon is attributed to microcirculatory impairment, possibly involving alpha-adrenergic vasoconstriction and microembolization.
Implications:
- Verapamil, a calcium channel blocker, effectively reversed the slow flow phenomenon and alleviated ischemic symptoms.
- The findings suggest the presence of vasoconstrictive mechanisms throughout the coronary system, particularly affecting microcirculation post-intervention.
- This case highlights the potential role of pharmacological agents in managing microcirculatory dysfunction after PCI.
Abstract:
We report on a 46-year-old male with unstable angina pectoris due to a total proximal occlusion of the left circumflex artery. At the side of a plaque rupture there was a thrombotic occlusion. With PTCA recanalization was possible, but a dissection occurred, therefore coronary stents were implanted. Besides an optimal morphological result and recurrent applications of nitroglycerin, the baseline blood flow velocity declined from initial 16 cm/s to 11 cm/s after PTCA down to 8.4 cm/s after stent implantation. Because peak flow velocity remained almost unchanged, the low baseline velocity ("slow flow phenomenon") did not lead to an impaired coronary flow velocity reserve (CFVR). Only after application of 1 mg verapamil, a sustained flow velocity on a higher baseline level was reached (17 cm/s), at the same time typical signs of ischemia in the ECG (ST-segment depressions) improved. Additionally, in the non-treated LAD there was an increase in coronary blood flow velocity from 10 cm/s up to 25 cm/s. The reduction in coronary blood flow velocity with increasing manipulations might be due to an impairment of the coronary microcirculations with increasing alpha-adrenergic vasoconstriction, a distribution of vasoactive agents and peripheral microembolizations. Only after administration of verapamil, a calcium channel blocker with non-specific anti-adrenergic effects, the slow flow was removed and ECG signs of ischemia improved. The blood flow velocity in the non-treated LAD was low at baseline and improved after verapamil. This phenomenon leads to the conclusion that mechanisms with vasoconstrictive effect are present in the whole coronary system, but these mechanisms are less pronounced in non-treated vessels.