Heart rate variability analysis and cardiac dysautonomia in ischemic stroke patients

Autonomic nervous system dysfunction after ischemic stroke predisposes to cardiovascular complications. We aimed to investigate cardiac autonomic activity in ischemic stroke patients using heart rate variability analysis, illustrating the sympathovagal balance at different sympathetic and parasympathetic activation tests.

We studied the dynamics of the linear and non-linear heart rate variability parameters in 31 left and 40 right middle cerebral artery ischemic stroke patients in rest condition and during autonomic activation tests (handgrip, standing, deep breathing and Valsalva maneuver). Data were compared with 30 age- and sex-matched healthy controls.

We found different responses after autonomic activation tests in stroke patients depending on the cortical lateralization of the ischemic lesion. In resting state, left hemisphere stroke patients presented enhanced parasympathetic modulation of the heart rate (higher values for RMSSD, pNN50, HF and SD1, p < 0.05), comparing to right hemisphere stroke patients. This second group displayed a reduced cardiac parasympathetic control in resting state and during autonomic activation tests (handgrip and standing tests) compared to the left hemisphere stroke group and controls. Non-linear parameters SD1 and DFA α1 showed a decrease of variability and complexity of the heart rate in right hemisphere stroke patients, ameliorated during vagal activation tests.

To prevent possible complications with vital risk, assessment of cardiovascular autonomic activity becomes a necessary stage in stroke patient management, facilitating immediate implementation of preventive and therapeutic strategies. Heart rate variability analysis in resting state and during autonomic activation tests allows identifying patients prone to sympathetic hyperactivity. New therapeutic perspectives for stroke management may emerge founded on the modulation of the autonomic nervous system.