Synthesis of the 12 lead electrocardiogram from a 3 lead semi-orthogonal subset using patient-specific linear transformation arrays

Continuous monitoring of the 12-lead electrocardiogram (ECG) could be diagnostically useful, but it is impractical because of the number of electrodes required. To determine if a patient-specific transformation of a 3-lead semiorthogonal subset could be used to synthesize an accurate 12-lead ECG, two patients were monitored for three consecutive days during hospitalizations for myocardial ischemia. Patient-specific transformations produced synthesized ECGs which were highly correlated with the recorded signals. Patient-specificity appeared essential for 12-lead synthesis, since transformation coefficients differed significantly between patients. Segmentation of the waveforms during the transformations improved the accuracy of the synthesized ECGs. A single patient-specific transformation array was used to synthesize 12-lead ECGs for three days in a patient with evolving ECG changes, suggesting that functionally equivalent 12-lead monitoring could be derived from three semiorthogonal leads