Higher heart rate associated with increased mortality

More evidence that the sympathetic nervous system dominance with progressive loss of parasympathetic nervous system tone that we measure with heart rate variability analysis (see numerous posts here) is a useful and important indicator is offered in a paper just published in the European Heart Journal. As the parasympathetic resources degrade with chronic illness, inflammation or aging heart rate tends to go up. The authors examined this phenomenon in relation to a specific set of cardiac patients:

"Although higher heart rate (HR) at baseline has been associated with an increased risk of cardiovascular (CV) and all-cause mortality, the relationship of in-treatment HR over time to mortality in hypertensive patients with ECG left ventricular hypertrophy (LVH) has not been examined."

They evaluated heart rate over time in 9190 patients with multiple analyses and adjustments for relevant variables, their data showed that:

"...higher in-treatment HR...remained strongly predictive of mortality: every 10 bpm higher HR was associated with a 16% increased adjusted risk of CV mortality and a 25% greater risk of all-cause mortality, with persistence or development of a HR ≥84 associated with a 55% greater risk of CV death and a 79% greater adjusted risk of all-cause mortality."

These are striking figures that attest to the predictive power of heart rate over time and the profound importance of autonomic (sympathetic and parasympathetic) nervous system regulation for global function. The authors conclude:

"Higher in-treatment HR on serial ECGs predicts greater likelihood of subsequent CV or all-cause mortality, independent of treatment modality, blood pressure lowering, regression of ECG LVH and changing QRS duration in hypertensive patients with ECG LVH. These findings support the value of serial assessment of HR for improved risk stratification in hypertensive patients."