Fig. 2

Mendelian randomization (MR) estimates the causal effect between tobacco and alcohol consumption and cardiac ECG indexes. A MR estimates are evaluated by the inverse variance weighted (IVW) method. B Scatterplot for MR-estimated individual variant regression coefficients for tobacco and alcohol consumption on PWD. C Scatterplot for MR-estimated individual variant regression coefficients for tobacco and alcohol consumption on PR interval. D Scatterplot for MR-estimated individual variant regression coefficients for tobacco and alcohol consumption on QT interval. PWD, P-wave duration; AUD, alcohol use disorders; PAU, problematic alcohol use; DrnkWk, drinks per week; CigDay, cigarettes per day; SmkInit, smoking initiation; β, effect sizes; 95%CI, 95% confidence interval