All about alternans

All about alternans

Here is all about alternans: Traube’s pulse, total pulsus alternans, diastolic pulsus alternans, right ventricular pulsus alternans, biventricular pulsus alternans and electrical alternans!

Traube’s pulse – pulsus alternans

Pulsus alternans or Traube’s pulse was described by Ludwig Traube in 1872 [1]. Pulsus alternans is nothing but alternating pulses having different volumes and is a feature of left ventricular dysfunction. It is well known that pulsus alternans can be augmented by a premature ventricular contraction [2].

A rare case of pulsus alternans due to 2:1 left bundle branch block (LBBB) has also been described [3]. The patient had normal coronaries and a left ventricular ejection fraction of 50%. The dyssynchrony associated with LBBB was thought to reduce left ventricular output during the block and consequent lower pulse volume in alternating beats.
Pulsus alternans with diastolic left ventricular dysfunction in the absence of systolic dysfunction was noted in a case of renal artery stenosis and pulmonary edema [4]. The pulsus alternans in this case disappeared after renal revascularization.
Treatment of heart failure causes improvement in pulsus alternans [5]. Similarly, improvement in pulsus alternans by ventilator therapy has been documented [6].

References

1. Conti AA. Nineteenth century “Traube’s pulse” and current “Cardiac alternans”: significant features in the history of cardiology. Clin Ter. 2012;163(2):e71-2.
2. Panutich MS, Knight BP. Augmentation of pulsus alternans by a premature ventricular beat. J Cardiovasc Electrophysiol. 2006 Aug;17(8):918.
3. Barold SS, Herweg B. Pulsus alternans caused by 2:1 left bundle branch block. J Interv Card Electrophysiol. 2005 Apr;12(3):221-2.
4. Kwan T, Feit A, Alam M, Mandawat MK, Clark LT. Pulsus alternans in diastolic left ventricular dysfunction–a case report. Angiology. 1997 Dec;48(12):1079-85.
5. Kobayashi S, Susa T, Tanaka T, Murakami W, Fukuta S, Okuda S, Doi M, Wada Y, Nao T, Yamada J, Okamura T, Yano M, Matsuzaki M. Low-dose β-blocker in combination with milrinone safely improves cardiac function and eliminates pulsus alternans in patients with acute decompensated heart failure. Circ J. 2012;76(7):1646-53. Epub 2012 Apr 5.
6. Haruki N, Takeuchi M, Yoshitani H, Otani K, Kuwaki H, Iwataki M, Abe H, Tamura M, Okazaki M, Otsuji Y. Immediate amelioration of mechanical pulsus alternans by adaptive servo-ventilation therapy. Heart Lung Circ. 2013 Apr;22(4):300-2.

Total pulsus alternans – pulsus alternans totalis

Total pulsus alternans – pulsus alternans totalis occurs when the force of contraction is so low in alternating beats that the aortic valve fails to open. It can be documented by simultaneous pulse and ECG recording. In an interesting case report, ECG monitor showed a rate of 160 per minute due to atrial tachycardia while the simultaneous pulse tracing showed a pulse rate of 80 per minute [1]. There was tachycardiomyopathy due to incessant tachycardia, producing left ventricular dysfunction. Pulsus alternans was abolished after successful radiofrequency catheter ablation of the atrial tachycardia.

Reference

1. Lu B, Roberts B, Sadaniantz A. Ineffective diastolic filling in tachycardia-induced cardiomyopathy with total pulsus alternans. J Am Soc Echocardiogr. 1997 Jan-Feb;10(1):88-92.

Diastolic pulsus alternans

Though there is no pulse felt in diastole, diastolic pulsus alternans has been described as the alternation of mitral inflow velocities. In one case it was due dilated cardiomyopathy and pulmonary embolism [1]. Another report was in severe heart failure [2]. Alternation in ventricular diastolic function can be documented both by Doppler echo and Tissue Doppler imaging [3].

Earlier description of diastolic pulsus alternans was alternation in the left ventricular diastolic pressures, as in a case of hypertrophic cardiomyopathy [4].

Reference

1. Szymanski P, Lipczynska M, Klisiewicz A, Hoffman P. “Like a sound and its echo”. Biventricular pulsus alternans. Heart. 2014 Jan;100(1):83, 90.
2. Perk G, Tunick PA, Kronzon I. Systolic and diastolic pulsus alternans in severe heart failure. J Am Soc Echocardiogr. 2007 Jul;20(7):905.e5-7.
3. Edwards P, Cohen GI. Both diastolic and systolic function alternate in pulsus alternans: a case report and review. J Am Soc Echocardiogr. 2003 Jun;16(6):695-7.
4. Yamakado T, Oomichi C, Maeda M, Yamada N, Shibata M, Kakimoto H, Nakano T. Left ventricular diastolic pulsus alternans in hypertrophic cardiomyopathy. Heart Vessels. 1994;9(5):969-72.

Right ventricular pulsus alternans

Right ventricular pulsus alternans can be isolated or associated with left ventricular pulsus alternans. Right ventricular and pulmonary artery pulsus alternans are demonstrated by cardiac catheterization studies. In one case of right ventricular pulsus alternans due to right ventricular infarction, improvement was obtained by coronary sinus pacing [1].

Doppler alternans and murmur alternans corresponding to right ventricular pulsus alternans has been noted in critical pulmonary stenosis with right ventricular dysfunction [2]. Pulmonary embolism and pulmonary hypertension [3] are other situations in which right sided pulsus alternans can be observed.

A rare occurrence of right sided pulsus alternans was in a case of prosthetic mitral valve thrombosis [4]. In an interesting case of right ventricular pulsus alternans in left ventricular diastolic dysfunction, pulsus alternans was demonstrated in right ventricle, pulmonary artery and pulmonary artery wedge positions, but not in the left ventricle or aorta [5].

References

1. Elmariah S, Shah RV, Kostis WJ, Hinson JT, Picard MH, Palacios IF. Coronary sinus pacing for the management of right ventricular and atrial infarction with isolated right ventricular pulsus alternans. Tex Heart Inst J. 2013;40(4):497-9.
2. Atiq M, Akhter S, Abdul Sattar S, Mohsin S, Aslam N. Murmur and Doppler alternans in critical pulmonary stenosis. Pediatr Cardiol. 2011 Oct;32(7):1004-7.
3. Ito M, Kodama M, Nagao T, Aizawa Y. Isolated right-sided pulsus alternans in pulmonary arterial hypertension. Intern Med. 2011;50(11):1257.
4. Abu-Ful A, Ilia R, Henkin Y. Right-sided pulsus alternans in prosthetic mitral valve thrombosis. J Invasive Cardiol. 2004 Apr;16(4):213-4.
5. Ilia R, Abu-Ful A, Weinstein JM, Merkin M. Right-sided pulsus alternans in diastolic left ventricular dysfunction. Catheter Cardiovasc Interv. 1999 Jul;47(3):336-9.

Biventricular pulsus alternans

Pulsus alternans is alternating volume of pulse, with a regular rhythm, mostly seen with severe left ventricular dysfunction. Biventricular and right ventricular pulsus alternans needs cardiac catheterization or Doppler echocardiography to demonstrate the alternating right ventricular or pulmonary artery systolic pressures. Biventricular pulsus alternans is much rarer than left ventricular pulsus alternans. One case reported was biventricular pulsus alternans due to anterior wall myocardial infarction [1]. Another report was an echocardiographic demonstration of biventricular pulsus alternans by echocardiography in a case of pulmonary embolism [2]. A combination of dilated cardiomyopathy and pulmonary embolism was responsible for biventricular pulsus alternans in another case [3]. The demonstration of alternans was the alternating left ventricular and right ventricular outflow velocities. A diastolic alternans was also described in the inflow velocities, though strictly the term diastolic pulsus alternans is not ideal because there is no pulse in diastole in this case!

References

1. Vidwan P, Stouffer GA. Biventricular pulsus alternans. Cardiol Res Pract. 2009;2009:703793.
2. Nguyen T, Cao LB, Tran M, Movahed A. Biventricular pulsus alternans: An echocardiographic finding in patient with pulmonary embolism. World J Clin Cases. 2013 Aug 16;1(5):162-5.
3. Szymanski P, Lipczynska M, Klisiewicz A, Hoffman P. “Like a sound and its echo”. Biventricular pulsus alternans. Heart. 2014 Jan;100(1):83, 90.

Electrical alternans

Electrical alternans is a phenomenon seen on the electrocardiogram with alternation in the amplitude of QRS complexes. The term electrical alternans totalis is used when the amplitudes of all the waves (P, QRS and T) show alternating amplitude. Electrical alternans totalis is seen in cardiac tamponade and is thought to be due to the swinging movement of the heart within the pericardial cavity. Electrical alternans may sometimes be associated with its mechanical counterpart: pulsus alternans. But most often the two are unrelated.

Isolated alternans of the ST segment and T wave also may occur. T wave alternans can be macroscopic or microvolt T wave alternans which can be detected only with special equipment. ST segment and T wave alternans have been reported in vasospastic angina and is thought to be the harbinger of life threatening arrhythmias. T wave alternans (both macroscopic and microvolt) have also been linked with ventricular arrhythmias and sudden cardiac death. T wave alternans has been noted in congenital long QT syndrome preceding torsades des pointes.