* Heart rate response to exercise (measured by
chronotropic reserve index)
In addition, it is now known that although acute caffeine consumption has a positive
chronotropic and inotropic effect, this effect is attenuated with chronic consumption.
A negative
chronotropic effect was profoundly exhibited by dexmedetomidine approximately 30-35 mins after starting bolus infusion, after which the heart rate remained stable in the range of 56-70/min in both the groups.
The study further confirmed that all exercise variables included in estimating physiological age were powerful predictors of survival, including exercise capacity,
chronotropic competence (heart rate response to exercise) and heart rate recovery.
The temporary pacemaker was placed in the patient's heart owing to hemodynamic instability Anamnesis obtained from the patient did not include a history of any cardiac event and negative
chronotropic drug use.
The study showed that poor sleepers had significantly more frequent hypertensive response to exercise,
chronotropic incompetence and reduced HRR at the 1st and 3rd min of peak exercise as compared to those with good sleep quality.
The negative and positive
chronotropic effects have been described using different exogenous NO donors.
Impaired
chronotropic and vasodilator reserves limit exercise capacity in patients with heart failure and a preserved ejection fraction.
Positive inotropic and negative
chronotropic effects of proton pump inhibitors in isolated rat atrium.
The effect of Egyptian cobra (Naja haje) on BP and
chronotropic response of the heart might be dose dependent as reported in a study based on an experiment conducted on rats (10).
In the setting of RA, it has been postulated that NSBB could produce further derangements on hemodynamics and decrease cardiac
chronotropic competence [21].
