|
| CORRESPONDENCE |
|
|
|
| Year : 2009 | Volume
: 41
| Issue : 1 | Page : 56 |
| |
Coronary flow and perfusion pressure
Pradeep Kumar1, Manish Goyal2
1 Department of Physiology, CSM Medical University, Lucknow, India
2 Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
Correspondence Address:
Pradeep Kumar
Department of Physiology, CSM Medical University, Lucknow
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0253-7613.48877
How to cite this article:
Kumar P, Goyal M. Coronary flow and perfusion pressure. Indian J Pharmacol 2009;41:56 |
Sir
I read carefully an article published in the Indian Journal of Pharmacology, Apr 2008 vol. 40 Issue 2, entitled 'Effects of low level lead exposure on blood pressure and function of the rat isolated heart'. [1]
The author has stated that the sub chronic exposure of lead does not show significant change in coronary flow in isolated perfused rat heart. It is well established that when oxygen consumption is kept constant, coronary blood flow is constant, independent of the coronary arterial pressure variations. When the pressure is kept constant, the flow varies linearly, with variations in oxygen consumption. [2] Variations in coronary arterial flow are directly coupled to the contraction-related intramural blood volume variations. [3] The interaction between flow variations and contraction is referred to as the intramyocardial pump. [4] Various metabolic substances, including vasodilators, produced locally at increased heart rate, can affect the perfusion pressure. [5] Therefore, to asses the coronary flow, tachycardia and positive inotropy is observed in this study. It is essential to keep constant perfusion pressure in isolated heart model, which was not done by the author. Hence, the author's statement is not justified.
| » References | |  |
| 1. | Reza B, Ali N, Azhdar H, Alireza A, Ali K. Effects of low-level lead exposure on blood pressure and function of the rat isolated heart. Indian J Pharmacol 2008;40:69-72.   |
| 2. | Vergroesen I, Noble MI, Spaan JA. Intramyocardial blood volume change in first moments of cardiac arrest in anesthetized goats. Am J Physiol Am 1987;253:H307-16. |
| 3. | Vergroesen I, Noble MI, Wieringa PA, Spaan JA. Quantification of O2 consumption and arterial pressure as independent determinants of coronary flow. Am J Physiol Br 1987;252:H545-53. |
| 4. | Dankelman J, Van der Ploeg CP, Spaan JA. Transients in myocardial O2 consumption after abrupt changes in perfusion pressure in goats. Am J Physiol 1996;270:H492-9. [PUBMED] [FULLTEXT] |
| 5. | Cornelissen AJ, Dankelman J, VanBavel EM, Spaan JA. Balance between myogenic, flow-dependent, and metabolic flow control in coronary arterial tree: A model study. Am J Physiol 2002;282:H2224-37. |
|
