Descriptive Controlled Study Regarding the Effects of Negative Chronotropic Agents on Lowering Heart Rate and Morning Surge in a Tertiary Care Hospital
Keywords:Beta blockers, non-dihydropyridine calcium channel blockers, morning surge, heart rate
ABSTRACT: Objective: To determine the optimal therapy for lowering the heart rate (HR) of cardio-compromised patients
by observing the effect of negative chronotropic agents. Methods: The retrospective study was conducted at the 24 Holter monitoring data centre of Agha Khan University Hospital from August 2010 to July 2011. Data was extracted by using a predesigned Performa on individuals with compromised cardiovascular disease. The sample population was categorized into four groups. Furthermore, two time intervals were set which included an early morning and a later period. Result: Of the 600 patients, 369 were males (61.5%) and 231 were females (38.5%) with a mean age of 54.9±19.2 years old. Average HR’s for patients on BB, CCB, combination therapy and drug naïve were 71.14±11.4 bpm, 72.38±11.95 bpm, 66.88±10.37 bpm and 76.47±13.63 bpm respectively (p value<0.01). In period I, 42.5% of patients on BB had the lowest HR with a mean of 50.47±10.27 bpm, 36% on nCCB had a mean of 51.7±13.6 bpm, 50% on combination had a mean of 47.38± 8.3 bpm and 39.86% of drug naïve patients had a mean of 50.87±10.47 bpm (p-value <0.8). In period II, 57.5% on BB had the lowest HR with a mean of 49.87±9.15 bpm, 64% on nCCB had a mean of 50.75±10.23 bpm, 50% on combination had a mean of 50.5±5.01 bpm and 61.14% of drug naïve patients had a mean of 52.04±11.56 bpm (p value<0.61). Conclusion: Negative chronotropic agents are highly effective in reducing a patient’s HR as compared to those who were drug naive.