Echocardiographic demonstration of decreased left ventricular dimensions and vigorous myocardial contraction during syncope induced by head-up tilt

Natalie and Norman Soref and Family Electrophysiology Laboratory, University of Wisconsin Medical School, Milwaukee.

Two-dimensional echocardiography was performed during a head-up tilt test in 11 control subjects (group I) and 18 patients with recurrent unexplained syncope. In four patients (group II), the head-up tilt test was negative at baseline and after isoproterenol infusion. Syncope was induced during baseline head-up tilt in nine patients (group III) and after isoproterenol challenge in five (group IV). The echocardiographic variables assessed were left ventricular end-systolic and end-diastolic areas and percent fractional shortening. At the end of head-up tilt, end-systolic area decreased by 4.5 +/- 1.3 and 3.0 +/- 1.2 cm2 in groups III and IV, respectively, compared with 0.5 +/- 0.7 and 0.2 +/- 0.1 cm2 in groups I and II, respectively (p less than 0.04). Similarly, end-diastolic area decreased by 5.5 +/- 2.6 cm2 in group III compared with 2.7 +/- 1.9 and 1.75 +/- 0.4 cm2 in group I and II, respectively (p less than 0.04). Additionally, at the end of the baseline study, fractional shortening was significantly greater in group III and group IV (43 +/- 5%) than in groups I and II (p less than 0.01). In conclusion, syncope induced by head-up tilt is associated with vigorous myocardial contraction and a significant decrease in left ventricular end-systolic dimensions. This left ventricular hypercontractility may play an important role in the pathogenesis of syncope induced by head-up tilt.

This article has been cited by other articles:

				I. Taneja, M. S. Medow, J. L. Glover, N. K. Raghunath, and J. M. Stewart Increased vasoconstriction predisposes to hyperpnea and postural faint Am J Physiol Heart Circ Physiol, July 1, 2008; 295(1): H372 - H381. [Abstract] [Full Text] [PDF]

				G. Fuca, M. Dinelli, L. Gianfranchi, S. Bressan, C. Lamborghini, and P. Alboni Do subjects with vasovagal syncope have subtle haemodynamic alterations during orthostatic stress? Europace, June 1, 2008; 10(6): 751 - 759. [Abstract] [Full Text] [PDF]

				G. Fuca, M. Dinelli, P. Suzzani, S. Scarfo, F. Tassinari, and P. Alboni The venous system is the main determinant of hypotension in patients with vasovagal syncope Europace, October 1, 2006; 8(10): 839 - 845. [Abstract] [Full Text] [PDF]

				S. Saravanan, M. Kocarev, R. C. Wilson, E. Watkins, M. O. Columb, and G. Lyons Equivalent dose of ephedrine and phenylephrine in the prevention of post-spinal hypotension in Caesarean section Br. J. Anaesth., January 1, 2006; 96(1): 95 - 99. [Abstract] [Full Text] [PDF]

				D. L. Jardine, I. C. Melton, I. G. Crozier, S. English, S. I. Bennett, C. M. Frampton, and H. Ikram Decrease in cardiac output and muscle sympathetic activity during vasovagal syncope Am J Physiol Heart Circ Physiol, May 1, 2002; 282(5): H1804 - H1809. [Abstract] [Full Text] [PDF]

				P. Alboni, M. Dinelli, P. Gruppillo, M. Bondanelli, K. Bettiol, P. Marchi, and E. C. d. Uberti Haemodynamic changes early in prodromal symptoms of vasovagal syncope Europace, January 1, 2002; 4(3): 333 - 338. [Abstract] [PDF]

				S. M. Kinsella and J. P. Tuckey Perioperative bradycardia and asystole: relationship to vasovagal syncope and the Bezold-Jarisch reflex Br. J. Anaesth., June 1, 2001; 86(6): 859 - 868. [Abstract] [Full Text] [PDF]

				R. Mosqueda-Garcia, R. Furlan, J. T. MD, and R. Fernandez-Violante The Elusive Pathophysiology of Neurally Mediated Syncope Circulation, December 5, 2000; 102(23): 2898 - 2906. [Full Text] [PDF]

				W Arthur and G C Kaye The pathophysiology of common causes of syncope Postgrad. Med. J., December 1, 2000; 76(902): 750 - 753. [Full Text]

				A. M. Fenton, S. C. Hammill, R. F. Rea, P. A. Low, and W.-K. Shen Vasovagal Syncope Ann Intern Med, November 7, 2000; 133(9): 714 - 725. [Abstract] [Full Text] [PDF]

				M E V Petersen, T R Williams, C Gordon, R Chamberlain-Webber, and R Sutton The normal response to prolonged passive head up tilt testing Heart, November 1, 2000; 84(5): 509 - 514. [Abstract] [Full Text]

				A. P. Fitzpatrick and A. Zaidi Tilt methodology in reflex syncope: emerging evidence J. Am. Coll. Cardiol., July 1, 2000; 36(1): 179 - 180. [Full Text] [PDF]

				W.-K. Shen, P. A. Low, R. F. Rea, C. M. Lohse, D. O. Hodge, and S. C. Hammill Distinct hemodynamic profiles in patients with vasovagal syncope: a heterogeneous population J. Am. Coll. Cardiol., May 1, 2000; 35(6): 1470 - 1477. [Abstract] [Full Text] [PDF]

				J. E. Liu, R. T. Hahn, K. M. Stein, S. M. Markowitz, P. M. Okin, R. B. Devereux, and B. B. Lerman Left Ventricular Geometry and Function Preceding Neurally Mediated Syncope Circulation, February 22, 2000; 101(7): 777 - 783. [Abstract] [Full Text] [PDF]

				F. M. Leonelli, K. Wang, J. M. Evans, A. R. Patwardhan, M. G. Ziegler, A. Natale, C. S. Kim, K. Rajikovich, and C. F. Knapp False positive head-up tilt:: Hemodynamic and neurohumoral profile J. Am. Coll. Cardiol., January 1, 2000; 35(1): 188 - 193. [Abstract] [Full Text] [PDF]

				D. Kosinski, B.P. Grubb, B.J. Karas, and S. Frederick Exercise-induced neurocardiogenic syncope: Clinical data, pathophysiological aspects, and potential role of tilt table testing Europace, January 1, 2000; 2(1): 77 - 82. [Abstract] [PDF]

				S.W. Parry and R.A. Kenny The management of vasovagal syncope QJM, December 1, 1999; 92(12): 697 - 705. [Full Text] [PDF]

				S.W. Parry and R.A. Kenny Tilt table testing in the diagnosis of unexplained syncope QJM, November 1, 1999; 92(11): 623 - 629. [Full Text] [PDF]

				E. Di Girolamo, C. Di Iorio, P. Sabatini, L. Leonzio, C. Barbone, and A. Barsotti Effects of paroxetine hydrochloride, a selective serotonin reuptake inhibitor, on refractory vasovagal syncope: a randomized, double-blind, placebo-controlled study J. Am. Coll. Cardiol., April 1, 1999; 33(5): 1227 - 1230. [Abstract] [Full Text] [PDF]

				R. Furlan, S. Piazza, S. Dell'Orto, F. Barbic, A. Bianchi, L. Mainardi, S. Cerutti, M. Pagani, and A. Malliani Cardiac Autonomic Patterns Preceding Occasional Vasovagal Reactions in Healthy Humans Circulation, October 27, 1998; 98(17): 1756 - 1761. [Abstract] [Full Text] [PDF]

				Z. Mallat, E. Vicaut, A. Sangare, J. Verschueren, G. Fontaine, and R. Frank Prediction of Head-Up Tilt Test Result by Analysis of Early Heart Rate Variations Circulation, July 15, 1997; 96(2): 581 - 584. [Abstract] [Full Text]

				H. L. Thomson, J. J. Atherton, F. A. Khafagi, and M. P. Frenneaux Failure of Reflex Venoconstriction During Exercise in Patients With Vasovagal Syncope Circulation, March 1, 1996; 93(5): 953 - 959. [Abstract] [Full Text]

				G. E. Tonnessen, J. I. Haft, J. Fulton, and D. G. Rubenstein The Value of Tilt Table Testing With Isoproterenol in Determining Therapy in Adults With Syncope and Presyncope of Unexplained Origin Arch Intern Med, July 25, 1994; 154(14): 1613 - 1617. [Abstract] [PDF]

				J. S. Sra, M. R. Jazayeri, B. Avitall, A. Dhala, S. Deshpande, Z. Blanck, and M. Akhtar Comparison of Cardiac Pacing with Drug Therapy in the Treatment of Neurocardiogenic (Vasovagal) Syncope with Bradycardia or Asystole N. Engl. J. Med., April 15, 1993; 328(15): 1085 - 1090. [Abstract] [Full Text]