Pulse wave intensity and ECG: A multisensor approach for the risk assessment in systolic heart failure

Blood pressure measurements are associated with paradoxical effects in patients with systolic heart failure. Parameters, which have been associated with increased risk, lie within a normal range in patients with impaired systolic function. This implies that the noninvasive detection of reduced ejection fraction from blood pressure alone is difficult and additional biosignals are needed. A typical approach is the usage of arterial Doppler flow velocity measurements, which also facilitates more advanced techniques such as wave intensity analysis. In this method, distinct peaks in forward and backward traveling waves can be detected and quantified. However, aiming for simple noninvasive measurement techniques, blood flow models solely based on information from the pressure curve have been developed to replace ultrasound measurements. These models could be extended and controlled with features from the electrocardiogram (ECG), which have been related to impaired systolic function. This work presents wave intensity parameters as well as ECG intervals from a patient with normal (nEF) and a patient with severely reduced ejection fraction (rEF). The wave peak corresponding to the first forward compression wave is markedly reduced in the rEF patient. Moreover, ECG intervals are prolonged, especially when corrected for heart rate. These exemplary results strengthen the idea that it might be feasible to use a multisensor approach based on arterial pressure readings and electrocardiogram features to detect impaired systolic function and thus enhance cardiovascular risk stratification.