Patients with atypical P-wave morphology were more often female ( 31 % vs. 24 % , P = 0.025 ) , had lower BMI ( 28 5 kg/m ( 2 ) vs. 29 5 kg/m ( 2 ) , P = 0.008 ) , had more ischemic CHF ( 60 % vs. 52 % , P = 0.026 ) and had smaller left atrial volumes ( 90 20 mL vs. 94 22 mL , P = 0.034 ) .