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[Pharmacologic modification of diastolic ventricular function in patients with coronary heart disease]
Insights
Diltiazem improved diastolic ventricular function in patients with ischemic heart disease without affecting systolic function. K-strophanthine enhanced systolic function and relaxation velocity, but had minimal impact on diastolic parameters.
Area of Science:
- Cardiology
- Pharmacology
- Physiology
Background:
- Ischemic heart disease (IHD) often impairs both systolic and diastolic ventricular function.
- Understanding the effects of cardiac pharmaceuticals on ventricular function is crucial for patient management.
- Diastolic dysfunction is a significant contributor to heart failure symptoms in IHD patients.
Purpose of the Study:
- To investigate the impact of diltiazem and k-strophanthine on diastolic ventricular function in patients with IHD.
- To assess the effects of these drugs on specific parameters of isovolumic relaxation and filling.
- To evaluate potential changes in systolic function parameters following administration.
Main Methods:
- Patients with IHD were administered either diltiazem or k-strophanthine.
- Echocardiography and pressure-volume analysis were used to measure diastolic parameters including time constant T, dt/T, peak filling rate (PFR), and filling fraction (FF).
- Systolic parameters such as ejection fraction (EF) and maximum pressure rise (dp/dt) were also monitored.
Main Results:
- Diltiazem significantly improved diastolic parameters: reduced time constant T (49±9 to 39±7 ms), increased dt/T (2.4±0.5 to 3.0±0.6 ms), increased PFR (2.08±0.65 to 2.34±0.67 EDV/sec), and increased FF (30±12% to 33±15%).
- K-strophanthine showed a trend towards reduced T (49±7 to 46±11 ms) but did not significantly alter dt/T, PFR, or FF.
- K-strophanthine improved systolic function, increasing EF (52±15% to 55±16%) and dp/dt (1855±468 to 2124±591 mmHg/s).
Conclusions:
- Diltiazem effectively enhances diastolic ventricular function in IHD patients without compromising systolic function.
- K-strophanthine primarily improves systolic ventricular function and the velocity of isovolumic relaxation.
- These findings suggest differential therapeutic effects of diltiazem and k-strophanthine on ventricular mechanics in IHD.
Abstract:
The influence of 2 different cardiac pharmaceutics on the diastolic ventricular function (VF) in patients with ischaemic heart disease was examined. Diltiazem, a calcium antagonist, and k-strophanthine led to a reduction of time constant T of the isovolumic relaxation from 49 +/- 9 to 39 +/- 7 msec (p less than 0.005), to an increase of the quotient dt/T from 2.4 +/- 0.5 to 3.0 +/- 0.6 msec (p less than 0.01), to an increase of the peak filling rate (PFR) from 2.08 +/- 0.65 EDV/sec to 2.34 +/- 0.67 EDV/sec (p less than 0.001), to an increase of the filling fraction (FF) from 30 +/- 12% to 33 +/- 15% (p less than 0.001). The ejection fraction (EF) and the maximum rise of pressure dp/dt did not change significantly. After k-strophanthine T was reduced from 49 +/- 7 to 46 +/- 11 msec (p less than 0.05). The increase of dt/T from 2.5 +/- 0.4 to 2.7 +/- 0.4 msec was not significant. The PFR with 2.16 +/- 0.7 and 2.08 +/- 0.8 EDV/sec and the FF with 32 +/- 14 and 34 +/- 18% did not show any significant changes. The EF rose from 52 +/- 15 to 55 +/- 16 (p less than 0.05) and dp/dt rose from 1855 +/- 468 to 2124 +/- 591 (p less than 0.05). Diltiazem improves the diastolic VF without deteriorating the systolic VF in patients with ischaemic heart disease. K-strophanthine improves the systolic VF and the velocity of the isovolumic relaxation. The other variables of the diastolic VF did not show any directed changes.