Table 1.

Initial staging of myocardial involvement in CCC.

Stages	ECG	Echocardiogram	Heart failure
A	Abnormal	Normal	Absent
B1	Abnormal	Abnormal, LVEF ≥ 45%	Absent
B2	Abnormal	Abnormal, LVEF < 45%	Absent
C	Abnormal	Abnormal	Compensable
D	Abnormal	Abnormal	Refractory

ECG, electrocardiogram; LVEF, left ventricular ejection fraction.