Effect of acute cigarette smoking on left and right ventricle filling parameters: a conventional and tissue Doppler echocardiographic study in healthy participants

Tissue-specific mitochondrial toxicity of cigarette smoke concentrate: consequence to oxidative phosphorylation

Cigarette smoke exposure is a well-known risk factor for developing numerous chronic health conditions, including pulmonary disease and cardiometabolic disorders. However, the cellular mechanisms mediating the toxicity of cigarette smoke in extrapulmonary tissues are still poorly understood. Therefore, the purpose of this study was to characterize the acute dose-dependent toxicity of cigarette smoke on mitochondrial metabolism by determining the susceptibility and sensitivity of mitochondrial respiration from murine skeletal (gastrocnemius and soleus) and cardiac muscles, as well as the aorta to cigarette smoke concentrate (CSC). In all tissues, exposure to CSC inhibited tissue-specific respiration capacity, measured by high-resolution respirometry, according to a biphasic pattern. With a break point of 451 ± 235 μg/mL, the aorta was the least susceptible to CSC-induced mitochondrial respiration inhibition compared with the gastrocnemius (151 ± 109 μg/mL; P = 0.008, d = 2.3), soleus (211 ± 107 μg/mL; P = 0.112; d = 1.7), and heart (94 ± 51 μg/mL; P < 0.001; d = 2.6) suggesting an intrinsic resistance of the vascular smooth muscle mitochondria to cigarette smoke toxicity. In contrast, the cardiac muscle was the most susceptible and sensitive to the effects of CSC, demonstrating the greatest decline in tissue-specific respiration with increasing CSC concentration (P < 0.001, except the soleus). However, when normalized to citrate synthase activity to account for differences in mitochondrial content, cardiac fibers' sensitivity to cigarette smoke inhibition was no longer significantly different from both fast-twitch gastrocnemius and slow-twitch soleus muscle fibers, thus suggesting similar mitochondrial phenotypes. Collectively, these findings established the acute dose-dependent toxicity of cigarette smoke on oxidative phosphorylation in permeabilized tissues involved in the development of smoke-related cardiometabolic diseases.NEW & NOTEWORTHY Despite numerous investigations into the mechanisms underlying cigarette smoke-induced mitochondrial dysfunction, no studies have investigated the tissue-specific mitochondrial toxicity to cigarette smoke. We demonstrate that, while aorta is least sensitive and susceptible to cigarette smoke-induced toxicity, the degree of cigarette smoke-induced toxicity in striated muscle depends on the tissue-specific mitochondrial content. We conclude that while the mitochondrial content influences cigarette smoke-induced toxicity in striated muscles, aorta is intrinsically protected against cigarette smoke-induced mitochondrial toxicity.

Healthcare knowledge of relationship between time series electrocardiogram and cigarette smoking using clinical records

Background

In the few studies of clinical experience available, cigarette smoking may be associated with ischemic heart disease and acute coronary events, which can be reflected in the electrocardiogram (ECG). However, there is no formal proof of a significant relationship between cigarette smoking and electrocardiogram results. In this study, we therefore investigate and prove the relationship between electrocardiogram and smoking using unsupervised neural network techniques.

Methods

In this research, a combination of two techniques of pattern recognition; feature extraction and clustering neural networks, is specifically investigated during the diagnostic classification of cigarette smoking based on different electrocardiogram feature extraction methods, such as the reduced binary pattern (RBP) and Wavelet features. In this diagnostic system, several neural network models have been obtained from the different training subsets by clustering analysis. Unsupervised neural network of clustering cigarette smoking was then implemented based on the self-organizing map (SOM) with the best performance.

Results

Two ECG datasets were investigated and analysed in this prospective study. One is the public PTB diagnostic ECG databset with 290 samples (age 17–87, mean 57.2; 209 men and 81 women; 73 smoking and 133 non-smoking). The other ECG database is from Taichung Veterans General Hospital (TVGH) and includes 480 samples (240 smoking, and 240 non-smoking). The diagnostic accuracy regarding smoking and non-smoking in the PTB dataset reaches 80.58% based on the RBP feature, and 75.63% in the second dataset based on Wavelet feature.

Conclusions

The electrocardiogram diagnostic system performs satisfactorily in the cigarette smoking habit analysis task, and demonstrates that cigarette smoking is significantly associated with the electrocardiogram.

Association of smoking and right ventricular function in middle age: CARDIA study

Objective

To evaluate the association of cigarette smoking and right ventricular (RV) systolic and diastolic functions in a population-based cohort of individuals at middle age.

Methods

This cross-sectional study included participants who answered the smoking questionnaire and underwent echocardiography at the Coronary Artery Risk Development in Young Adulthood year 25 examination. RV systolic function was assessed by echocardiographic-derived tricuspid annular plane systolic excursion (TAPSE) and by right ventricular peak systolic velocity (RVS'), while RV diastolic function was evaluated by early right ventricular tissue velocity (RVE'). Multivariable linear regression models assessed the relationship of smoking with RV function, adjusting for age, sex, race, body mass index, systolic blood pressure, total cholesterol, high-density lipoprotein (HDL) cholesterol, diabetes mellitus, alcohol consumption, pulmonary function, left ventricular systolic and diastolic function and coronary artery calcium score.

Results

A total of 3424 participants were included. The mean age was 50±4 years; 57% were female; and 53% were black. There were 2106 (61%) never smokers, 750 (22%) former smokers and 589 (17%) current smokers. In the multivariable analysis, current smokers had significantly lower TAPSE (β=-0.082, SE=0.031, p=0.008), RVS' (β=-0.343, SE=0.156, p=0.028) and RVE' (β=-0.715, SE=0.195, p<0.001) compared with never smokers. Former smokers had a significantly lower RVE' compared with never smokers (β=-0.414, SE=0.162, p=0.011), whereas no significant difference in RV systolic function was found between former smokers and never smokers.

Conclusions

In a large multicenter community-based biracial cohort of middle-aged individuals, smoking was independently related to both worse RV systolic and diastolic functions.

Effects of chronic cigarette smoking on myocardial deformation parameters by two-dimensional speckle tracking echocardiography

BACKGROUND

Cigarette smoking causes myocardial damage with several mechanisms such as sympathetic nervous system activation, oxidative stress, and endothelial dysfunction. Chronic smokers have an increased risk of morbidity and mortality associated with cardiac events. We aimed to compare the myocardial deformation parameters between chronic smokers and nonsmoker healthy population.

METHOD

Forty-two healthy participants (mean age 33.48 ± 10.00 years) without smoking history, 40 participants (mean age 33.98 ± 9.27 years) who had been smoking were prospectively included. In addition to conventional echocardiographic measurements, global longitudinal strain (GLS) of left ventricle (LV), GLS of right ventricle (RV), left atrial strain, and strain rate were analyzed.

RESULTS

Smokers had lower peak early diastolic velocity (E) and E/a (early diastolic velocity/late diastolic velocity) ratio in mitral inflow (70.0 ± 13.9 cm/sec vs 77.1 ± 13.3 cm/sec, P = .023; 1.4 ± 0.4 vs 1.7 ± 0.4, P = .011; respectively). Peak early diastolic velocity of mitral valve septal annulus (Em) and Em/Am ratio (peak early diastolic velocity of mitral valve/late diastolic velocity of mitral valve) (11.0 ± 2.1 cm/sec vs 12.1 ± 2.4 cm/sec, P = .023; 1.2 ± 0.3 vs 1.4 ± 0.4, P = .039; respectively) were lower in smokers. LV GLS and RV GLS were significantly lower in smokers (-17.6% ± 3.01 vs -19.2% ± 2.5; P = .013, -18.9% ± 4.4 vs -21.0% ± 4.5; P = .039; respectively).

CONCLUSION

Impaired LV and RV deformation were found in chronic smokers in our study. Although there was no statistically significant difference with left ventricular ejection fraction, LV GLS which is the early indicator of LV systolic dysfunction was lower in chronic smokers. The assessment of early harmful effects of smoking on left and right ventricle might be evaluated with speckle tracking echocardiography.

Functional, Cellular, and Molecular Remodeling of the Heart under Influence of Oxidative Cigarette Tobacco Smoke

Passive and active chronic cigarette smoking (CS) remains an international epidemic and a key risk factor for cardiovascular disease (CVD) development. CS-induced cardiac damage is divided into two major and interchangeable mechanisms: (1) direct adverse effects on the myocardium causing smoking cardiomyopathy and (2) indirect effects on the myocardium by fueling comorbidities such as atherosclerotic syndromes and hypertension that eventually damage and remodel the heart. To date, our understanding of cardiac remodeling following acute and chronic smoking exposure is not well elucidated. This manuscript presents for the first time the RIMD (oxidative stress (R), inflammation (I), metabolic impairment (M), and cell death (D)) detrimental cycle concept as a major player in CS-induced CVD risks and direct cardiac injury. Breakthroughs and latest findings in the field with respect to structural, functional, cellular, and molecular cardiac remodeling following chronic smoking exposure are summarized. This review also touches the genetics/epigenetics of smoking as well as the smoker's paradox and highlights the most currently prominent pharmacological venues to mitigate CS-induced adverse cardiac remodeling.

Echocardiographic consequences of smoking status in middle-aged subjects

BACKGROUND

Smoking is known to have many short- and long-term cardiovascular effects. Cardiac index (CI), which is cardiac output indexed to body surface area, is considered to be a valid measure of cardiac performance. We investigated whether there were any differences in CI or other echocardiographic variables between never smokers, ex-smokers, and current smokers in a cardiopulmonary healthy population.

METHODS

Subjects (n=355) from a previous population-based respiratory questionnaire survey (never smokers, ex-smokers, and current smokers without significant chronic obstructive lung disease) were examined with echocardiography, and CI (L/min/m² ) was calculated.

RESULTS

Current smokers had a higher CI than never smokers 2.61±0.52 L/min/m² vs. 2.42±0.49 L/min/m² (P<.01). Ex-smokers had a nonsignificant, numerically higher value for CI than never smokers 2.54±0.54 L/min/m² vs. 2.42±0.49 L/min/m² (P>.05). Smoking status had no significant effect on other echocardiographic variables.

CONCLUSION

We conclude that currents smokers without known cardiac disease or significant chronic obstructive lung disease show signs of slightly altered hemodynamics.

Acute effects of cigarette smoking on the cardiac diastolic functions

BACKGROUND

Smoking is an independent risk factor for coronary heart diseases and it increases all causes of cardiovascular morbidity and mortality.

AIM OF THE WORK

To assess the acute effect of cigarette smoking on ventricular diastolic functions (LV and RV) in healthy, young, and slim smokers.

METHODS

Thirty volunteers who had recently commenced smoking (less than one year) and who smoked 1-2 cigarettes per day, underwent ECG, 2D and M-mode echocardiography, standard Doppler echocardiography, pulsed TDI (tissue Doppler imaging) on septal and lateral side of mitral annulus and lateral tricuspid annulus. Vp values were measured. The investigator asked them to hold smoking for at least two days after which echocardiographic examination was conducted before smoking one cigarette and the second examination conducted immediately after smoking one cigarette containing at least 0.4 mg of nicotine.

RESULTS

Doppler findings over the mitral valve showed the E wave was significantly reduced from 82.7 ± 10.4 to 74.6 ± 10.4 after smoking; the A wave increased; the E/A ratio was reduced from 1.5 ± 0.3 to 1.2 ± 0.2; the E' septal significantly decreased (15.3 ± 2.4 vs. 11.2 ± 1.1) after smoking, and the E/E' ratio increased from 5.5 ± 1.1 to 6.7 ± 1.1. Doppler findings over the tricuspid valve showed the E wave was reduced from 60.6 ± 9.7 to 52.7 ± 9.6; the A wave increased from 42.2 ± 6.5 to 50.1 ± 6.6; and the E/A ratio decreased (1.45 ± 0.25 vs. 1.06 ± 0.19). The E' significantly decreased from 14.1 ± 1.8 to 10.9 ± 2.4, while the A' increased (10.2 ± 2.4 vs. 12.7 ± 3.6) after smoking; and the IVRT of the RV was significantly prolonged from 62.9 ± 7.5 to 68.7 ± 7.9 after smoking. The Vp was markedly reduced from 67.8 ± 8 to 55.2 ± 3.5 after smoking. These findings reflected on the LV filling pressure (LVFvp) which increased from 9.8 ± 1.4 to 10.5 ± 1.3 after smoking. All changes were statistically significant at P < 0.001.

CONCLUSIONS

Our study reveals that cigarette smoking can result in significant acute alteration in the diastolic functions of both ventricles.

Chronic nicotine effects on left ventricular function in healthy middle-aged people: an echocardiographic study

AIMS

Cigarettes and Swedish snuff influence the cardiovascular system in many ways. Cigarette and snuff usage have been linked with an acute impairment in several diastolic cardiac parameters during intake. The aim of this study is to investigate whether long-term usage of Swedish snuff or cigarettes also causes a more permanent impairment of systolic and/or diastolic cardiac parameters in the left ventricle in otherwise healthy middle-aged snuffers and smokers.

METHODS AND RESULTS

Eighty-seven age-matched volunteers were included and examined with echocardiography. The volunteers were divided into three subgroups; one group with non-tobacco users, one group with long-term smokers and finally one group with long-term snuffers. The smokers and snuffers were instructed not to use these products for at least 5 h before the examination. The systolic and diastolic cardiac parameters were collected at one time. Most of the systolic parameters measured were unaltered between the tobacco subgroups and non-tobacco users, and therefore, no alteration of significance was found in systolic parameters. Also, almost all of the diastolic parameters measured were not significantly impaired in the tobacco subgroups compared with non-tobacco users. However, the deceleration time (DT) was slightly prolonged (P<0·05) and thus statistically significant in the tobacco subgroups. This finding is somewhat difficult to interpret but may be seen as random.

CONCLUSIONS

This study reveals that most systolic- and diastolic cardiac parameters are not chronically significantly altered in middle-aged long-term tobacco users compared with age-matched non-tobacco users.

Acute effects on the ventricular function in Swedish snuffers: an echocardiographic study

AIMS

Cigarettes and Swedish snuff contain nicotine, which influence the cardiovascular system. Cigarette smoke has been shown to give an acute impairment in diastolic heart parameters. The systolic and diastolic heart function in snuff users is not thoroughly enough investigated. The aim of this study was to investigate if Swedish snuff will give an acute decrease in systolic and diastolic heart parameters in the left and right ventricles in healthy Swedish snuffers.

METHODS AND RESULTS

Thirty healthy volunteers were examined with echocardiography. The study involved recordings from four different times: before snuff intake, 5 and 30 min after intake and finally 30 min after snuff withdrawal. The systolic and diastolic heart parameters were collected with conventional echocardiographic methods. In addition, the heart frequency and blood pressure response were measured. The pulse and blood pressure response were significantly altered (P < 0.01) during the test. Left ventricular ejection fraction and the amplitudes of mitral and tricuspid annulus motion did not alter significantly. The main finding in the study was the significant decrease (P < 0.05) in several diastolic heart parameters for both the left and right ventricles.

CONCLUSIONS

This study shows that snuff intake causes a significant decrease in E/A ratio and a delay in ventricular relaxation and therefore a decrease in diastolic heart function in the left and right ventricles. The mechanism behind these alterations is probably very complex, but a combination of nicotine effects and loading conditions is probably the main factor.

Relation of cardiovascular risk factors to right ventricular structure and function as determined by magnetic resonance imaging (results from the multi-ethnic study of atherosclerosis)

The effect of cardiovascular risk factors on the left ventricle is well known but their effect on right ventricle has not been studied using advanced imaging techniques. The purpose of the present study was to determine the relation between the cardiovascular risk factors and right ventricular (RV) structure and function and its interaction with the left ventricle. Cardiac magnetic resonance images from 4,204 participants free of clinical cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis were analyzed. Multivariate linear regression models were used to study the cross-sectional association between individual RV parameters and risk factors. All RV parameters, except for ejection fraction, decreased with age (p <0.0001). The RV mass was positively associated with systolic blood pressure (+0.4 g, p <0.0001) and high-density lipoprotein cholesterol (+0.2 g, p <0.0001). It was inversely related with diastolic blood pressure (-0.3 g, p <0.0001) and total cholesterol (-0.2 g, p <0.01). The RV end-diastolic volume was positively associated with systolic blood pressure (+1.6 ml, p <0.01) and high-density lipoprotein cholesterol (+1.8 ml, p <0.0001). It was inversely related with diastolic blood pressure (-2.2 ml, p <0.01), total cholesterol (-1.4 ml, p <0.0001), current smoking (-2.7 ml, p <0.05), and diabetes mellitus (-3.1 ml, p <0.01). The RV ejection fraction was positively associated with systolic blood pressure (+1.0%, p <0.0001), high-density lipoprotein cholesterol (+0.4%, p <0.0001) and inversely with diastolic blood pressure (-0.7%, p <0.0001). In conclusion, the mass and volumes of the right ventricle decrease with age. Cardiovascular risk factors, especially blood pressure and high-density lipoprotein cholesterol, are associated with subclinical changes in the RV mass and volume.

Chronic cigarette smoking affects left and right ventricular long-axis function in healthy young subjects: a Doppler myocardial imaging study

OBJECTIVE

Cigarette smoking is one of the major risk factors for coronary artery disease. However, chronic smoking has additional cardiac adverse effects independent of coronary atherosclerosis. We assessed the possible effects of chronic smoking on left and right ventricular (LV, RV) long-axis function using Doppler myocardial imaging (DMI).

METHODS

Forty otherwise healthy smokers (mean age = 26+/-3 years) and 40 age-matched nonsmoking controls enrolled. Standard echocardiography protocol was followed by DMI. Peak systolic (V(S)), early (V(E)) and late diastolic (V(A)) velocities, peak systolic strain (S), and strain rate (SR) were measured from septal, lateral, and RV free walls.

RESULTS

The baseline characteristics of two groups were similar. There were significant differences regarding Doppler myocardial velocity, S, and SR indices. Septal V(E) (P < 0.04), S (P < 0.0001) and SR (P < 0.02) were significantly reduced in smokers. For both lateral and RV free wall, V(S) (P < 0.003, P < 0.002, respectively), V(E) (P < 0.0001, P < 0.002, respectively), S (P < 0.0001 for both), and SR (P < 0.0001, P < 0.002, respectively) were significantly reduced in smokers. There were significant correlations between the amount of smoking and septal, lateral, and RV free wall S and SR.

CONCLUSIONS

Chronic cigarette smoking causes alterations in long-axis systolic and diastolic functions of right and left ventricles in healthy young subjects. These changes can be accurately detected with Doppler myocardial velocity and SR imaging.