Effects of smoking on coronary blood flow velocity and coronary flow reserve assessed by transthoracic Doppler echocardiography.
BACKGROUND
Smoking is a well-known risk factor for cardiovascular disease. Coronary blood flow velocity (CFV) can be measured directly with transthoracic Doppler echocardiography (TTDE) which is conducted immediately after smoking.


OBJECTIVE
The purpose of this study was to evaluate the chronic and acute effects of smoking on coronary blood flow and coronary flow reserve (CFR) by the use of TTDE.


METHODS
Healthy volunteers (11 smokers and 9 nonsmokers) with a mean age of 27 +/- 3 years were included. Smoking was abstained for at least 4 hours before the study. CFV was measured at the distal left anterior descending coronary artery by TTDE at baseline and during intravenous adenosine infusion (140 microg/kg per minute) in all participants. For smokers, CFV was measured immediately after consecutively smoking two cigarettes and during adenosine infusion.


RESULTS
CFR and coronary vascular resistance index (CVRI) showed no significant difference between nonsmokers and smokers (CFR: 3.5 +/- 0.8 vs 3.6 +/- 0.6, P = ns, CVRI: 0.28 vs 0.28, P = ns) at baseline. CFR significantly decreased (3.6 +/- 0.6 to 2.8 +/- 0.7, P = 0.008) and CVRI markedly increased (0.28 to 0.35, P = 0.012) after smoking.


CONCLUSIONS
After 4 hours of abstinence from smoking, CFR and CVRI in smokers were similar to those of nonsmokers. However, consecutively smoking two cigarettes acutely reduced CFR and increased CVRI. These findings suggested that smoking could reduce coronary blood flow immediately, even in healthy people.
Park
Seong-Mi
SM
Division of Cardiology, Korea University Hospital, Seoul, Korea.
Shim
Wan-Joo
WJ
Song
Woo-Hyuk
WH
Lim
Do-Sun
DS
Kim
Young-Hoon
YH
Ro
Young-Moo
YM
D000241:Adenosine; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D015150:Echocardiography, Doppler; D006801:Humans; D008297:Male; D012907:Smoking / Q000009:adverse effects*; D018709:Statistics, Nonparametric; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D000241:Adenosine