Subcostal M-mode echocardiography of the right atrial wall in evaluation of cardiac arrhythmias and pacing.

Subcostal M-mode echocardiography of the right atrial wall in combination with the simultaneously recorded nondiagnostic electrocardiogram is useful in the recognition of various rhythm disturbances. Each arrhythmia has a characteristic right atrial wall motion pattern. Flat and hidden P-waves can be accurately detected throughout the cardiac cycle and supraventricular tachycardias with aberration can be distinguished from ventricular tachycardia with AV dissociation. This echocardiographic technique is of special value in the follow-up of physiological pacemakers because atrial capture and sensing malfunctions can be reliably detected. Finally, it can also facilitate the programming of atrial channels output + sensitivity, and recognition of the pacemaker syndrome.