Introduction

To investigate the relationship between right ventricular strain and smoking-related parameters in smoking volunteers using CVI software.

Material and Methods

Twenty-two smokers (all men, mean age 39.7 ± 7.4 years) were enrolled in the study. All of them underwent cardiac scan at a 3.0T MR from December 2017 to March 2018. The operators conducted smoking status surveys detailedly and obtained smoking-related parameters which including Daily smoking, smoking years, and smoking index, followed by a heart scan on MR to obtain the original image of the heart, the original image of the heart was passed to the Report Card 4.4 workstation to measure the right ventricular ejection fraction (RVEF). Right ventricular strain parameters were measured in CVI post-processing software, which including: right ventricular radial strain (RVRS), right ventricular radial strain rate (RVRSR), right ventricular circumferential strain (RVCS), right ventricular circumferential strain rate (RVCSR) , Right ventricular longitudinal strain (RVLS) and right ventricular longitudinal strain rate (RVLSR). The right ventricular endocardial and epicardial contours need to be manually outlined at three different levels when measuring right ventricular strain using CVI software as shown in Figure.1. The correlation between right ventricular strain and smoking-related parameters in smoking volunteers was analyzed.

Results

There was a positive statistical correlation between RVRS and Daily smoking (p=0.027,r=0.471), smoking years (p=0.000,r=0.701) and smoking index (p=0.005,r=0.572) respectively. Similarly, There was a positive statistical correlation between RVCS and Daily smoking (p=0.043,r=0.436), smoking years (p=0.001,r=0.670) and smoking index (p=0.010,r=0.537) respectively. There was no statistical correlation between RVLS and Daily smoking (p>0.05), smoking years (p>0.05) and smoking index (p>0.05) respectively.

Discussion

Long-term chronic smoking is prone to cause a variety of chronic lung diseases and cardiovascular diseases. Studies have shown that cardiovascular disease (including pulmonary hypertension) is the most common cause of smoking-related death and has a high risk of death^[1]. Myocardial strain can be uesd to evaluate local myocardial function and wall motion accurately^[2] and can be used to detect the cardiovascular effects of smoking early before the ejection fraction is abnormal. In this study, RVRS and RVCS showed a statistical correlation with smoking-related parameters while RVEF of 22 smoking volunteers were in a normal range, which was consistent with previous ultrasound findings.

Conclusion

Myocardial strain can reflect the influence of smoking on the right ventricle when the ejection fraction remains normal. There was a positive statistical correlation between myocardial radial strain , circumferential strain and smoking-related parameters respectively. It can be seen that the right ventricle has a compensatory capacity for smoking on the heart for a certain period of time.

Acknowledgements

The author thank the study subjects, the radiologist at Dalian Medical University, and all the people involved.