Background: Previous studies have focused mainly on the acute effects of smoking on the diastolic function of the heart. The present study was conducted to demonstrate the chronic effects of smoking on the diastolic functional parameters of the heart, including transmitral M- mode coloured flow propagation velocity (Vp), among relatively younger asymptomatic adults.
Method: Hundred smokers with histories of incessant smoking for at least one year prior to the time of the investigation were included in the prospectively designed study as group I. Group II consisted of 35 non-smokers, matched for age and gender. Addiction to smoking was graded according to the modified Fagerström test for nicotine dependence (M-FNDT). Each smoker was designated by a nicotine dependence index (NDI) according to the M-FNDT. Groups I and II were compared with respect to major diastolic functional parameters on transthoracic echocardiography (TTE), including the E/A ratio, deceleration time (DT), isovolumic relaxation time (IVRT) and Vp, along with basic clinical and echocardiographic parameters.
Results: Thirty one smokers in group 1 and 5 non-smokers in group 2 were excluded from the study according to the pre-defined exclusion criteria. Therefore 69 smokers (mean age: 30 ± 4.9 years, M/F: 32/37) in group I were compared with 30 non-smokers (mean age: 31.4 ± 4.8 years, M/F: 15/15) in group II. In group I the mean values of E/A and Vp were significantly lower (p < 0.001), whereas the mean values of IVRT and DT were significantly higher (p < 0.001) than in group II. In group I the value of NDI was positively correlated with the values of DT and IVTR (p < 0.001) and negatively correlated with the value of Vp (p < 0.001).
Conclusion: Conventional and relatively new parameters of cardiac diastolic function, in particular Vp, were found to be impaired in smokers demonstrating the chronic adverse effects of smoking on the diastolic function of the heart. The severity of this impairment was closely correlated with the degree of addiction to smoking. (Cardiol J 2007; 14: 281-286)