|
|
| Year : 2011
| Volume
: 14 | Issue : 2 | Page
: 165-166 |
|
| Pulsus alternans after aortic valve replacement: A preventable yet a possible risk of cardiac manipulation - Fact or Fiction? |
|
|
Amit Jain
Department of Anaesthesia & Intensive Care,Post Graduate Institute of Medical Education and Research, Chandigarh, India
Click here for correspondence address and
email
| Date of Web Publication | 25-May-2011 |
|
|
 |
|
How to cite this article:
Jain A. Pulsus alternans after aortic valve replacement: A preventable yet a possible risk of cardiac manipulation - Fact or Fiction?. Ann Card Anaesth 2011;14:165-6 |
How to cite this URL:
Jain A. Pulsus alternans after aortic valve replacement: A preventable yet a possible risk of cardiac manipulation - Fact or Fiction?. Ann Card Anaesth [serial online] 2011 [cited 2021 Feb 27];14:165-6. Available from: https://www.annals.in/text.asp?2011/14/2/165/81581 |
The Editor,
I read with interest the letter to the editor, "Pulsus alternans (P ALT ) after aortic valve replacement: Intraoperative recognition and role of TEE" by Gadhinglajkar. [1] The inference of the authors seems to be simple, but a closer look reveals the omission of many implicating factors that would have contributed in the induction of P ALT . Therefore, I dispute the conclusions.
I believe that the preoperative poor left ventricular ejection fraction (LVEF) in a patient with severe aortic regurgitation could be a strong predictor for the development of P ALT . in the immediate post-bypass period following aortic valve replacement. Further, the dose of epinephrine infused and the preload maintained during weaning from cardiopulmonary bypass seem to be suboptimal. Adequate fluid therapy and increasing the infusion of epinephrine with or without afterload reduction using vasodilator therapy could have improved the stroke volume and avoided beat-to-beat variability in the systolic blood pressure. Thus, the induction of P ALT . following cardiac manipulation seemed to be multifactorial and could have been potentially prevented.
The LVEF measured on echocardiography in a patient with severe aortic regurgitation (AR) overestimates effective ejection fraction, i.e., the forward ejection fraction. Thus, the LVEF of 25% with severe AR indicates severely failed heart and the development of P ALT . during and following surgical manipulation in such a heart should not bring a surprise. Further, though the hemodynamics before the surgical manipulation was stable, the authors did not mention cardiac output/cardiac index and systemic vascular resistance that bear implication on the induction of mechanical alternans in their patient.
In addition, the undiagnosed decrease in preload, even in the presence of acceptable vital signs, seemed to be overlooked. The progressive decrease in the velocity time integral during controlled breathing suggests that the preload was inadequate during the period of cardiac handling.
Further, the left atrial pressure in the grossly dilated left ventricle was only 3 mmHg.
Elevated afterload in presence of poor left ventricular function could be another possible cause for P ALT . in such a patient with stable blood pressure. Further, afterload reduction with vasodilator therapy could be used to produce the disappearance of pulsus alternans. [2]
Atrial pacing in a heart with global left ventricular hypocontractility could be another factor predisposing to the induction of P ALT . [3] Rapid heart rates would accentuate the starling phenomenon because of the effects of heart rate on the time available for diastolic filling. Experimental studies have shown that mechanical alternans is easier to induce by rapid pacing in hearts from animals with congestive heart failure. [4] Further, rapid atrial pacing evoked P ALT . could be abolished by intravenous infusion of epinephrine. [5] In addition to increasing the slow inward calcium current and calcium release from the sarcoplasmic reticulum, b-adrenergic receptor agonist also accelerates the rate of relaxation and increases the diastolic filling period. [4] All these effects may be important in preventing or abolishing mechanical alternans.
The implications for the factors I mentioned are well substantiated in the literature. Thus, the episode seemed to have evolved following cardiac handling against a background of what seemed to be benign. Although I differ with the authors' observations and the issue may be contentious because of its interwoven complexity, they must be complemented for their deft handling of a difficult case.
 References | |  |
| 1. | Gadhinglajkar S, Sreedhar R, Jayant A. Pulsus alternans after aortic valve replacement: Intraoperative recognition and role of TEE. Ann Card Anaesth 2010;13:181-4. 
[PUBMED]  |
| 2. | Cheng TO, Leet CJ. Pulsus alternans. Its response to amyl nitrite inhalation. Angiology 1984;35:115-21.
[PUBMED] [FULLTEXT] |
| 3. | Euler DE. Cardiac alternans: Mechanisms and pathophysiological significance. Cardiovasc Res 1999;42:583-90.
[PUBMED] [FULLTEXT] |
| 4. | Narayan P, McCune SA, Robitaille PM, Hohl CM, Altschuld RA. Mechanical alternans and the force-frequency relationship in failing rat hearts. J Mol Cell Cardiol 1995;27:523-30.
[PUBMED] [FULLTEXT] |
| 5. | Badeer HS, Ryo UY, Gassner WF, Kass EJ, Cavaluzzi J, Gilbert JL, et al. Factors affecting pulsus alternans in the rapidly driven heart and papillary muscle. Am J Physiol 1967;213:1095-101.
[PUBMED] [FULLTEXT] |
Correspondence Address:
Amit Jain
Department of Anaesthesia & Intensive Care, Postgraduate Institute of Medical Education and Research,Chandigarh
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0971-9784.81581
|
|
| This article has been cited by | | 1 |
Authorsę reply |
|
| Gadhinglajkar, S., Sreedhar, R., Jayant, A. | | Annals of Cardiac Anaesthesia. 2011; 14(2): 166-167 | | [Pubmed] | |
|
|
|
|
|
|
|
|
