Circulation. 1998;98:1042-1043
(Circulation. 1998;98:1042-1043.)
© 1998 American Heart Association, Inc.
Attenuation of Unfavorable Sympathetic Hyperactivity Induced by Long-Term Physical Training in Postinfarction Patients: Fact or Speculation?
A. Tenenbaum, MD;
; J. Shemesh, MD
Cardiac Rehabilitation Institute,
Chaim Sheba Medical Center,
Tel-Hashomer, Israel
To the Editor:
Recently, Giannuzzi et al1 eloquently
described the beneficial effect of long-term exercise training on left
ventricular remodeling in postinfarction patients. An
earlier report from Coats et al2 demonstrated
that training can improve autonomic function (mainly in terms of RR
variability and norepinephrine spillover) in patients
with chronic heart failure but failed to show significant changes in
resting catecholamine levels after a short-term exercise
program.
In an attempt to explain their findings, Giannuzzi et al used a
series of reports describing the reduction of catecholamine
levels by exercise training in subjects with normal left
ventricular function3 4 and
speculated that this effect exists in patients with left
ventricular dysfunction as well. However, this phenomenon
is no longer conjectural because it has been demonstrated clearly in
postinfarction patients with severe left ventricular
dysfunction after long-term exercise
rehabilitation.5 Moreover, that
study5 also showed a beneficial effect of the
rehabilitation program on atrial natriuretic peptide. We
hope that clarification of these points will provide additional support
for the findings of Giannuzzi and his team.
References
-
Giannuzzi P, Temporelli PL, Corrà U,
Gattone M, Giordano A, Tavazzi L, for the ELVD Study Group. Attenuation
of unfavorable remodeling by exercise training in postinfarction
patients with left ventricular dysfunction: results of the
Exercise in Left Ventricular Dysfunction (ELVD) trial.
Circulation. 1997;96:1790–1797.[Abstract/Free Full Text]
-
Coats AJS, Adamopoulos S, Radaelli A, McCance A, Meyer
TE, Bernardi L, Solda PL, Davey P, Ormerod O, Forfar C, Conway J,
Sleight P. Controlled trial of physical training in chronic heart
failure: exercise performance, hemodynamics,
ventilation, and autonomic function. Circulation. 1992;85:2119–2131.[Abstract/Free Full Text]
-
Goldsmith RL, Bigger JT Jr, Steinman RC, Fleiss JL.
Comparison of 24-hour parasympathetic activity in endurance-trained and
untrained young men. J Am Coll Cardiol. 1992;20:552–558.[Abstract]
-
Cooksey JD, Reilly P, Brown S, Bomeze H, Cryer PE.
Exercise training and plasma catecholamines in patients
with ischemic heart disease. Am J Cardiol. 1978;42:372–376.[Medline]
[Order article via Infotrieve]
-
Shemesh J, Grossman E, Peleg E, Steinmetz A, Rosenthal
T, Motro M. Norepinephrine and atrial
natriuretic peptide responses to exercise testing in
rehabilitated and nonrehabilitated men with ischemic
cardiomyopathy after healing of anterior wall acute
myocardial infarction. Am J Cardiol. 1995;75:1072–1074.[Medline]
[Order article via Infotrieve]
Response
Pantaleo Giannuzzi, MD;
; Ugo Corrà, MD
"Salvatore Maugeri" Foundation,
IRCCS,
Division of Cardiology,
Rehabilitation Institute of Veruno, Italy
We greatly appreciate the letter of Drs Tenenbaum and Shemesh,
who give us the opportunity to provide additional comments concerning
the role of exercise training in the remodeling process among
postinfarction patients with left ventricular dysfunction
and the long-term effect of physical training on the autonomic balance
and neurohormonal activation.
After the initial conflicting results, an increasing body of
evidence has now demonstrated clearly that patients with poor left
ventricular function after an uncomplicated myocardial
infarction may benefit from regular exercise training without any
additional deterioration of ventricular volumes and
function.1 2 More importantly,
we2 recently documented in a large group of
postinfarction patients with left ventricular dysfunction
that long-term exercise training may attenuate the unfavorable
remodeling process and even improve both regional and global function
over time. We3 also reported similar results in
preliminary form in patients with chronic heart failure, in whom
training actually lessened left ventricular dilatation and
dysfunction.
Exercise training has been shown to increase functional work
capacity and at the same time to reduce catecholamine
levels and vascular peripheral resistances and enhance
heart rate variability and baroreflex gain, both in subjects with
normal ventricular function as well as in patients with
left ventricular dysfunction and heart failure. Shemesh et
al4 briefly reported significantly lower levels
of resting norepinephrine and atrial
natriuretic peptide in postinfarction patients with reduced
ejection fraction who were undergoing long-term cardiac rehabilitation.
This result and previous observations strongly indicate a lower
sympathetic activity after training. The real point of speculation in
our article was not the existence of this effect but the possible
interplay of this factor with others, including improvement in
myocardial blood flow.
Although we did not assess neurohormonal changes, the features of the
training response we found in our study are consistent with the
usual response to regular exercise, including reduction in resting
heart rate and blood pressure and in exercise heart rate and
rate-pressure product.2 Indexes of heart rate
variability also improved after training, particularly in patients with
an initial autonomic derangement as expressed by a reduced heart rate
variability.5 These findings reflect beneficial
changes in autonomic balance and/or baroreflex gain and are in
agreement with the attenuation of the vasoconstrictor influences,
mainly due to sympathetic hyperactivity, and the increased vagal tone
described after training. The beneficial changes in autonomic balance
induced by physical training may actually limit the deleterious effects
of sympathetic hyperactivity on left ventricular remodeling
and function.
References
-
Dubach P, Myers J, Dziekan G, Goebbels U, Reinhart W,
Vopgt P, Ratti R, Muller P, Miettunen R, Buser P. Effect of exercise
training on myocardial remodeling in patients with reduced left
ventricular function after myocardial infarction:
application of magnetic resonance imaging. Circulation. 1997;95:2060–2067.[Abstract/Free Full Text]
-
Giannuzzi P, Temporelli PL, Corrà U, Gattone M,
Giordano A, Tavazzi L, for the ELVD Study Group. Attenuation of
unfavorable remodeling by exercise training in postinfarction patients
with left ventricular dysfunction: results of the Exercise
in Left Ventricular Dysfunction (ELVD) trial.
Circulation. 1997;96:1790–1797.
-
Giannuzzi P, Temporelli PL, Corrà U, Balestroni
GL, Tavazzi L. Long-term exercise training in patients with chronic
heart failure: results of the ELVD-CHF (Exercise in Left
Ventricular Dysfunction and Chronic Heart Failure) trial.
Circulation. 1997;96(suppl I):I-711. Abstract.
-
Shemesh J, Grossmann E, Peleg E, Steinmetz A,
Rosenthal T, Motro M. Norepinephrine and atrial
natriuretic peptide responses to exercise testing in
rehabilitated and nonrehabilitated men with ischemic
cardiomyopathy after healing of anterior wall acute
myocardial infarction. Am J Cardiol. 1995;75:1072–1074.
-
Lanfranchi P, Mazzuero G, Temporelli PL, Giannuzzi P.
Exercise training and autonomic balance in the exercise in left
ventricular dysfunction (ELVD) trial.
Circulation. 1997;96(suppl I):I-638. Abstract.
