Comparison of myocardial catecholamine balance in chronic congestive heart failure and in angina pectoris without failure
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Patients with chronic heart failure show significantly higher myocardial norepinephrine release, suggesting increased cardiac sympathetic tone. This imbalance in catecholamine levels is a key finding in heart failure research.
Area of Science:
- Cardiology
- Physiology
- Pharmacology
Background:
- Heart failure (HF) is characterized by complex neurohormonal alterations.
- Understanding myocardial catecholamine balance is crucial for managing HF.
- Previous studies have indicated sympathetic nervous system overactivity in HF.
Purpose of the Study:
- To investigate the myocardial catecholamine balance in patients with chronic heart failure (CHF).
- To compare norepinephrine (NE) and epinephrine (E) levels in arterial and coronary sinus blood between CHF patients and those with angina pectoris (AP) without HF.
- To determine the net myocardial release of NE and E in these patient groups.
Main Methods:
- Systemic hemodynamics, coronary sinus blood flow, and arterial/coronary sinus NE and E concentrations were measured.
- 30 patients with CHF and 25 patients with AP (no HF) were included.
- Net myocardial NE and E release was calculated based on concentration gradients and blood flow.
Main Results:
- Patients with CHF exhibited depressed left ventricular function (lower stroke work index, higher pulmonary capillary wedge pressure).
- Coronary sinus blood flow was comparable between CHF and AP groups.
- Arterial and coronary sinus NE concentrations were significantly higher in CHF patients, resulting in approximately 20-fold higher net myocardial NE release compared to AP patients.
- Arterial E and myocardial E uptake were similar in both groups.
Conclusions:
- Patients with chronic heart failure demonstrate significantly elevated net myocardial norepinephrine release.
- This increased NE release likely reflects enhanced cardiac sympathetic tone in response to the failing heart.
- The precise mechanisms driving this enhanced myocardial NE release require further investigation.
Abstract:
To evaluate myocardial catecholamine balance in heart failure, systemic hemodynamics, coronary sinus blood flow, and arterial and coronary sinus venous norepinephrine (NE) and epinephrine (E) concentrations were determined in 30 patients with chronic left ventricular failure (CHF), and in 25 patients with angina pectoris (AP) but without heart failure. In the group with CHF, stroke work index was lower (CHF 20 +/- 9, AP 53 +/- 13 g-m/m2, p less than 0.001) and pulmonary capillary wedge pressure higher (CHF 28 +/- 8, AP 11 +/- 4 mm Hg, p less than 0.001), indicating depressed left ventricular function. Coronary sinus blood flow was similar in 2 groups (CHF 97 +/- 70, AP 73 +/- 32 ml/min, difference not significant). In the group with CHF, arterial (634 +/- 582 pg/ml) and coronary sinus venous (1,038 +/- 1,014 pg/ml) NE concentrations were significantly higher than in the group with AP (arterial 185 +/- 135, coronary sinus 231 +/- 167 pg/ml, p less than 0.001). The net myocardial NE release in patients with CHF was approximately 20 times higher than that in patients with AP (CHF 38,548 +/- 48,622, AP 2,245 +/- 10,242 pg/min, p less than 0.001). Arterial E and myocardial E uptake was similar in both groups. Although mechanisms for increased myocardial net NE release remains unknown, it probably represents enhanced cardiac sympathetic tone in response to heart failure.