Alternans of blood pressure and heart rate in patients with dilated cardiomyopathy

Alternans is characterized by changes of interbeat intervals (IBI) and blood pressure amplitudes (BPA) on a beat-to-beat basis. We hypothesize that an impaired myocardial performance influences the duration and amplitude of the alternans and could enhance the diagnostics in patients with dilated cardiomyopathy (DCM). ECG and non-invasive blood pressure were recorded from 91 DCM patients and 45 healthy controls. Alternans phenomena were detected as a beat preceded and followed by beats that had higher or lower values in the respective modality. Mean duration of IBI alternans (p = 0.032) as well as BPA alternans (systolic: p < 0.001; diastolic: p = 0.021) and maximum alternans durations (IBI: p = 0.003; systolic BPA: p<0.001; diastolic BPA: p = 0.004) were significantly enlarged in DCM. Alternans analysis seems to be useful for an enhanced classification and functional assessment of DCM patients.