Detection of Exercise-Induced Reversible RightVentricular Wall Motion Abnormalities Using

Echocardiographic Determined TricuspidAnnular Motion

Mahbubul Alam, MD, PhD, and Bassem A. Samad, MD

In recent years, some studies have shown the impor-tance of assessing right ventricular (RV) function in

patients with coronary artery disease.1,2 Because of itscomplex shape, analysis of RV function has beenconsidered to be difficult.3,4 Recent echocardiographicstudies have shown that the descent of the base of theleft ventricle, i.e., the atrioventricular (AV) plane dis-placement, during the cardiac cycle can be used as asimple method to evaluate left ventricular function.5–7

RV systolic descent of the AV plane, i.e., the tricuspidannular motion (TAM) during the cardiac cycle, isrelated to systolic function in a way similar to that ofthe left ventricle.8,9 To our knowledge, there havebeen no reports on the effect of exercise on TAM.Using an echocardiographic recording of the TAM,we analyzed the exercise-related changes in RV wallmotion in patients with coronary artery disease.

• • •We started the study with 28 consecutive patients

with normal rest electrocardiograms and diagnosedwith coronary artery disease, either from a typicalhistory of effort angina pectoris or earlier positiveexercise electrocardiography. None had clinical orelectrocardiographic signs of previous myocardial in-farction. Six patients were excluded: 3 because ofunsatisfactory recording of the TAM immediately af-ter exercise and 3 because of normal findings in thecoronary angiogram. All patients had a normal ejec-tion fraction and none had evidence of congestiveheart failure or valvular or congenital heart disease.Nine consecutive healthy subjects without a history ofcardiac disease or systemic hypertension and withnormal findings at rest and exercise electrocardiogra-phy and rest echocardiography served as controls.

All echocardiographic recordings were undertakenwith patients in the left lateral decubitus position. Theechocardiographic apparatus used was an Aloka SSD-870 (Tokyo, Japan) with a 2.5-MHz transducer. Dif-ferent cardiac dimensions were recorded from theapical 4-chamber views. Left ventricular ejection frac-tion was assessed using the amplitude of the AV planedisplacement as described elsewhere.5,6 TAM was re-corded at the RV free wall from the apical 4-chamberview at rest, immediately after a bicycle exercise teston a bed adjacent to the bicycle and also 10 to 20minutes afterward. The optimal transducer position

was marked on the patient’s chest before the bicycleergometer test to fascilitate recording immediatelyafter exercise. Care was taken to maximize RV size toavoid errors in size assessment resulting from apicalforeshortening. Recordings were stored on videotapeswith the possibility of frame-by-frame analysis. RVsystolic function was assessed from the total magni-tude of the TAM toward the apex in systole and wasexpressed in millimeters. This was done by freezingthe apical 4-chamber view at end-diastole and end-systole. The difference in the distance between anouter fixed point of the cardiac apex at one site and thetricuspid annulus at the free wall in end-diastole orend-systole at the other site gives the magnitude ofTAM (Figure 1). The recordings and calculations ofdifferent parameters were performed without access toangiographic data and vice versa.

The exercise test was performed with the patientsand healthy subjects in the sitting position, using anelectrically braked bicycle ergometer with stepwiseincrements of workload. The criteria for terminationof the test were the occurrence of any of the followingend points: exhaustion, severe angina, severe dyspnea,ST-segment depression of$2 mm, or a reduction insystolic blood pressure of.10 mm Hg. An abnormalexercise test was defined as a horizontal or downslop-ing ST-segment depression of$1 mm occurring at0.08 second after termination of the QRS interval,development of typical angina pectoris, or a bloodpressure decrease as mentioned above.

Coronary angiograms were recorded in patientswithin an average of 2 weeks (range 1 to 37 days)from exercise echocardiography. The cine films werereviewed on a Tagarno cine projector (Horsens, Den-mark) and coronary arterial lesions were estimatedvisually. A significant coronary artery lesion was de-fined as a$50% reduction in the luminal diameter ofa major coronary artery or one of its major branches.Stenoses of the right coronary artery were divided intoproximal lesions if the stenosis was located before theorigin of the RV branches and distal lesions if thelocation was distal to the RV branches.

Results are expressed as mean6 1 SD. Compari-sons between the groups were made using thet test.Qualitative variables are expressed as percentages. Totest interobserver variability, measurements of TAMwere made independently by 2 investigators and thevariation was tested using thet test.

The basic clinical parameters and echocardio-graphic dimensions are listed in Table I. Both normalsubjects and patients had normal ejection fractions.The amplitude of the TAM toward the apex in systole

From the Department of Medicine, Cardiology Section, KarolinskaInstitute at South Hospital (Sodersjukhuset), Stockholm, Sweden. Dr.Alam’s address is: Department of Medicine, Section of Cardiology,South Hospital (Sodersjukhuset), S-118 83 Stockholm, Sweden. E-mail: mahbubul.alam@medklin.sos.sll.se. Manuscript received March31, 1998; revised manuscript received and accepted July 29, 1998.

103©1999 by Excerpta Medica, Inc. 0002-9149/99/$–see front matterAll rights reserved. PII S0002-9149(98)00789-9

was similar both in healthy subjects and in patients atrest (246 3 mm, range 20 to 29, in healthy subjects,and 236 3 mm, range 14 to 27, in patients). Twenty-two patients had significant stenosis in at least one ofthe coronary arteries or one of its major branches(Table II). Nine patients had proximal and 3 distalright coronary artery stenosis, along with otherchanges.

The recording of postexercise echocardiogramswas completed within 60 to 90 seconds after thebicycle test. All healthy subjects had an increase inTAM of at least 5 mm. The mean increase was 8 mm(range 5 to 10, p,0.001). The interobserver variationin calculating TAM was not significant (p.0.05); themaximum variation for an individual subject was 2mm (range 0 to 2). Patients had a different pattern ofexercise-related TAM compared with baseline. Of 9patients with proximal right coronary artery stenosis,7 had at least a 6-mm decrease in TAM compared withbaseline. None of the 13 patients with distal rightcoronary artery stenosis or stenosis in the left-sidedcoronary arteries had any decrease in TAM (Table II).

The exercise-related changes in healthy subjects andpatients returned to normal 10 to 20 minutes after theexercise test. Taking an exercise-related decrease ofTAM of $4 mm (i.e., double the individual variationin the interobserver variation test) as a cutoff point fordetecting proximal right coronary artery stenosis givesa sensitivity of 78% and a specificity of 100%.

• • •At rest, the amplitude of TAM at the RV free wall

was similar in healthy subjects and patients with cor-onary artery disease without any known previousmyocardial infarction. Previous studies using 2-di-mensional–guided M-mode recording of TAMshowed similar amplitudes of displacement.8,9 Themagnitude of TAM, which is approximately 24 to 25mm, is much higher than the descent of the left ven-tricular base, which is approximately 14 to 15 mm, asshown in previous studies.5,6 This reflects the predom-inance of longitudinal shortening of the RV free wallwith little shortening of its width.10 M-mode echocar-diography at the resting position may be more precisein recording the different events that occur duringTAM.8,9 In this study, we used frame-by-frame freez-ing pictures with fixed points, one at the epicardialmargin of the cardiac apex and the other at the freewall of the tricuspid annulus in end-diastole and end-systole. This method was used to minimize the lateraldeviation of the TAM during the cardiac cycle, whichcould otherwise be significant immediately after ex-ercise. Because the epicardial site of the cardiac apexremains virtually immobile during the cardiac cy-cle,11,12 our way of calculating TAM at the free wallshould give the optimal value of this motion along itslong axis.

Immediately after the exercise test there was asignificant increase in TAM in all healthy subjects.Although no angiograms were recorded in healthysubjects, they performed a maximum exercise testwithout ischemic signs at exercise electrocardiogra-phy. Therefore, it is highly probable that they do nothave any significant coronary stenosis. The increase inTAM in these subjects is a valuable adaptive mecha-nism for the increase in RV contractility, which wouldbe essential for the attainment of normal systolic emp-tying in shorter periods as a result of exercise-relatedtachycardia.

Compared with healthy subjects, patients with cor-onary artery disease had a variable pattern of TAMimmediately after the exercise test. The RV free wallis perfused by the right coronary artery via acutemarginal branches. Significant stenosis of the proxi-mal right coronary artery would therefore produceexercise-related reversible ischemia of the RV wall.Although patients with right coronary artery stenosisare few in number in this study, 78% of the patientswith proximal right coronary artery stenosis had areversible decrease of at least 6 mm in the amplitudeof the TAM compared with at least a 5-mm increase inhealthy subjects. However, none of the patients withstenoses in the distal right coronary artery or in theleft-sided coronary arteries had any decrease in TAM.Thus, it is reasonable to assume that a reversible

FIGURE 1. Recording of tricuspid annular motion from apical4-chamber views. The distance between the fixed epicardial siteof the apex and the tricuspid annulus at the right ventricular freewall in end-diastole was measured (A). In the same way, thedistance from the apex to tricuspid annulus in end-systole wasalso calculated (B). The difference between these 2 distances(A-B) gives the amplitude of tricuspid annular motion, which isexpressed in mm.

TABLE I Basic Clinical and Echocardiographic Parameters inPatients and Healthy Subjects.

Healthy SubjectsCoronary Artery

Disease

Age (yr) 55 6 4 (50–60) 59 6 8 (40–75)Men/women 8/1 17/5Left ventricle (mm) 47 6 4 (42–55) 50 6 3 (45–56)Left atrium (mm) 37 6 3 (32–41) 37 6 4 (29–43)Right ventricle (mm) 33 6 4 (26–37) 32 6 5 (25–39)Right atrium (mm) 34 6 4 (30–40) 33 6 5 (23–44)Ejection fraction (%) 63 6 5 (55–70) 65 6 6 (55–75)Exercise-heart rate

(beats/min)170 6 14 (155–195) 120 6 20 (802151)

Results are expressed as mean 6 SD (range).

104 THE AMERICAN JOURNAL OF CARDIOLOGYT VOL. 83 JANUARY 1, 1999

decrease in TAM in patients with proximal right cor-onary artery stenosis is an expression of exercise-related reversible RV ischemia. The recording of theTAM is simple from the apical 4-chamber views. Theinterobserver variation is low and the maximum indi-vidual variation is 2 mm for calculations of the TAMin an individual subject. Taking double this value, i.e.,a $4-mm depression of the TAM as a positive test,the sensitivity is 78% and specificity 100% for detect-ing patients with proximal right coronary artery ste-nosis.

Recording of TAM by echocardiography is sim-ple and reflects RV systolic function due to longi-tudinal shortening of the RV free wall. Exercise-related reversible changes in TAM may be used toidentify patients with proximal right coronary ar-tery stenosis.

1. DellItalia LJ, Starling MD, Crawford MH, Boros BL, Chaudhuri TK,O‘Rourke RA. Right ventricular infarction: identification by hemodynamic mea-surements before and after volume loading and correlation with noninvasivetechniques.J Am Coll Cardiol1984;4:931–939.

2. San Roman JA, Vilacosta I, Rollan MJ, Castillo JA, Alonso J, Duran JM,Gimeno F, Vega JL, Sanchez-Harguindey L, Fernandez-Aviles F. Right ventric-ular asynergy during dobutamine-atropine echocardiography.J Am Coll Cardiol1997;30:430–435.3. DellItalia LJ, Starling MR, Walsh RA, Badke FR, Lasher JC, Blumhardt R.Validation of attenuation-corrected equilibrium radionuclide angiographic deter-minations of right ventricular volume: comparison with cast-validated biplanecineventriculography.Circulation 1985;72:317–326.4. Fisher E, Dubrow RA, Hastreiter AR. Right ventricular volumes in congenitalheart disease.Am J Cardiol1975;36:67–75.5. Alam M, Rosenhamer G. Atrioventricular plane displacement and left ven-tricular function.J Am Soc Echocardiogr1992;5:427–433.6. Alam M, Hoglund C, Thorstrand C, Hellekant C. Haemodynamic significanceof the atrioventricular plane displacement in patients with coronary artery disease.Eur Heart J1992;13:194–200.7. Simonson JS, Schiller NB. Descent of the base of the left ventricle: anechocardiographic index of left ventricular function.J Am Soc Echocardiogr1989;2:25–35.8. Alam M, Hoglund. Assessment by echocardiogram of left ventricular diastolicfunction in healthy subjects using the atrioventricular plane displacement.Am JCardiol 1992;69:565–568.9. Hammarstro¨m E, Wranne B, Pinto FJ, Puryear J, Popp RL. Tricuspid annularmotion. JAm Soc Echocardiogr1991;4:131–139.10. Rushmer RF, Crystal DK, Wagner G. Functional anatomy of ventricularcontraction. Circ Res1953;1:162–170.11. Lundback S. Cardiac pumping and the function of the ventricular septum.Acta Physiol Scand1986 (suppl);550:1–101.12. Slager CJ, Hooghoudt TEH, Serruys PW, Schuurbiers JC, Reiber JH, MeesterGT, Verdouw PD, Hugenholtz PG. Quantitaive assessment of regional leftventricular motion using endocardial landmarks.J Am Coll Cardiol1986;7:317–326.

TABLE II Tricuspid Annular Motion at Rest and Immediately After Exercise in Relation to Coronary Artery Anatomy in Patients WithCoronary Artery Disease

No. Age (yr) r-TAM (mm) ex-TAM (mm) diff-TAM (mm) Ex-ECG ex-HR Coronary Stenosis

Group I: Patients With Proximal Right Coronary Artery Stenosis

1. 60 22 11 2 11 (50%) 1 132 Prox R, LAD, LC2. 67 26 19 2 7 (27%) 1 80 Prox R, LAD3. 64 25 17 2 8 (32%) 1 140 Prox R, LAD4. 65 27 17 2 10 (37%) 1 104 Prox R, LAD, LC5. 62 27 21 2 6 (22%) 1 115 Prox R, LAD, LC6. 75 25 18 2 7 (28%) 2 112 Prox R, LAD, LC7. 65 23 14 2 9 (39%) 1 151 Prox R, LAD, LC8. 56 20 28 1 8 (40%) 1 150 Prox R, LM, LAD, LC9. 69 14 20 1 6 (43%) 1 85 Prox R, LAD, LC

Group II: Patients Without Proximal Right Coronary Artery Stenosis

10. 74 24 28 1 4 (17%) 1 125 Dis R, LAD, LC11. 51 21 27 1 6 (28%) 1 122 Dis R, LAD12. 63 23 27 1 4 (17%) 1 135 Dis R, LAD13. 60 24 31 1 7 (29%) 1 135 LM14. 51 24 32 1 8 (33%) 1 120 LAD15. 63 20 25 1 5 (25%) 1 106 LM, LAD, LC16. 63 26 34 1 8 (31%) 2 122 LC17. 53 25 31 1 6 (24%) 2 150 LC18. 50 21 26 1 5 (24%) 1 112 LAD19. 55 20 29 1 9 (45%) 1 131 LAD20. 53 25 30 1 5 (20%) 1 102 LAD21. 40 23 24 1 1 (4%) 2 98 LAD, LC22. 51 22 23 1 1 (4%) 2 110 LAD

diff-TAM 5 increase (1) or decrease (2) in the amplitude of tricuspid annular motion from rest to postexercise in millimeters (and in percentage); Dis 5 distal,ex-ECG 5 exercise electrocardiography (1 5 positive) (2 5 negative); ex-HR 5 maximum heart rate at exercise; ex-TAM 5 amplitude of tricuspid annular motionimmediately after exercise; LAD 5 left coronary anterior descending; LC 5 left circumflex; LM 5 left main; No. 5 serial number, Prox 5 proximal; R 5 right; r-TAM 5

amplitude of tricuspid annular motion in millimeter at rest.

BRIEF REPORTS 105