Kerala Heart Journal -Roopesh George

Original article

Kerala Heart J  2016; 6(2):xx-xx.  



RIGHT VENTRICULAR FUNCTION IN PATIENTS WITH FIRST ACUTE MYOCARDIAL INFARCTION

Roopesh George*, Arun George,
Gagan Sharma, Jayaraj K, Antony TP, Abdhul Khadher


Corresponding author


Roopesh George,

Associate Professor, Dept.of cardiology,

Amala Medical college, Thrissur.

Email: rupeshgeorge@gmail.com



ABSTRACT

Background: Right ventricular(RV) dysfunction predicts poor prognosis in acute myocardial infarction. The sensitivity of clinical findings for RVMI is as low as 10%. Right side ECG leads give information of right ventricular free wall only. As Tissue Doppler study of  RV gives better information of global RV function we intended to do this study.

 

Objectives: The present study was conducted to investigate the effect of different infarction sites on right ventricular (RV) functional changes by echocardiogram in patients with first acute ST-elevation myocardial infarction.

 

Methodology: The study was a descriptive cross sectional study with the study setting from the In-patients of the departments of internal medicine and cardiology. Clinical findings and echocardiography of  consecutive 200 patients with myocardial infarction during the period of Dec 2012 to Dec 2013, who met the inclusion and exclusion criteria, were taken. Age, gender distribution, risk factors, clinical findings, ECG and Echocardiographic findings including, TAPSE, Tissue Doppler MPI, ejection fraction were analysed.

 

Results: The prevalence of RV dysfunction in echo cardiogram was comparable in both AWMI and IWMI. In our study 30.3% (n= 27) had abnormal TAPSE in AWMI and 34.2% (n = 38) in IWMI. Tissue Doppler MPI abnormality was seen in 34 patients (38.2%) with Anterior Wall MI and 55 patients (49.5%) with inferior wall MI. Impairment of  LV Ejection fraction was more frequent in AWMI (84.3%{ n = 75 } ) than in IWMI (18.9%).

 

Conclusion: Even though, clinical RV involvement was more in cases of inferior wall myocardial infarction, echocardiographically, the incidence was comparable in  both inferior wall MI and anterior wall MI.

 

Key Words:  RV  function , myocardial infarction, TAPSE , Tissue Doppler MPI.

 

 

 

 

RIGHT VENTRICULAR FUNCTION IN PATIENTS WITH FIRST ACUTE MYOCARDIAL INFARCTION

 

INTRODUCTION

Right ventricular dysfunction in acute coronary syndrome is traditionally being said to be associated with acute Inferior Wall MI, when proximal right coronary artery is the culprit 1,2. It is because right ventricle free wall is exclusively being supplied by right coronary artery. It is now recognized that free wall contraction contributes only a part of total systolic volume. Changes of the right ventricle contraction of the interventricular septum and the crista supraventricularis may be far more important than that of the free wall. Since the major blood supply for inter ventricular septum is from left anterior descending artery, acute anterior wall MI can also lead to RV dysfunction. The damage portion of left ventricle muscle fibers can also affect RV function due to its synctitial arrangement.

 

 

AIM AND OBJECTIVES:

 

Our aim was to investigate the effect of different infarction sites on right ventricular (RV) functional changes by echocardiogram in patients with first acute ST-elevation myocardial infarction.

 

 

MATERIALS AND METHODS

 

The study was a descriptive cross sectional study with the study setting from the Inpatients of the department of internal medicine and Cardiology at Amala Institute of Medical Sciences, Thrissur. The study subjects were all first time acute ST segment elevation myocardial infarction patients .

Study period:

One year

 

Inclusion criteria:

 

All patients with first time acute ST segment elevation MI was included in the study.

ST segment elevation of >1mm in two contiguous leads (V1-V6 for anterior MI and L2, L3, aVf for IWMI) with cardiac enzyme elevation was the criteria for infarction.

 

Exclusion criteria:

 

Patients with prior MI .

Patients with poor transthoracic echocardiography window .

Patient with valvular heart disease, congenital heart disease, LBBB or paced rhythm, Cardiomyopathy.

Sampling method:

 Sample size was 200 patients.

 After obtaining informed consent, patients demographic data, clinical findings, ECG and Echocardiography findings were recorded in a pre-structured Performa.

 Echocardiography evaluation of both RV and LV function was done within 48 hrs of admission.

 

Tools and techniques:

 

All patients included in the study were evaluated clinically and echocardiographically at the time of admission. Detailed echocardiographic evaluation of both left and right ventricular function was done within 48 hours.

 

EVALUATION OF LV FUNCTION:

 

End-diastolic dimension (EDD), End systolic dimension (ESD)

Ejection fraction (EF) (modified Simpson method),

Doppler tissue imaging of medial and lateral mitral annulus, mid segment of interventricular septum (IVS) and left ventricular lateral wall.

 

EVALUATION OF RV FUNCTION:

 

Included dimensions of RV and Inferior vena cava (IVC),

Pulsed Doppler imaging of flow of Tricuspid, Hepatic vein, RVOT and Pulmonary artery (at end expiration).

Doppler tissue imaging (DTI) of medial and lateral part of Tricuspid annulus is performed in apical four chamber view.

Strain imaging of right ventricular free wall and interventricular septum.

Study variables: Right ventricular function.

 

 

STATISTICAL ANALYSIS:

 

Data obtained were coded and entered into Microsoft Excel spreadsheet and analyzed using Statistical Package for Social Sciences (SPSS) version 16 for Windows

Description of socio demographic characteristics, clinical features, echocardiographic and angiogram findings were done in terms of frequencies and percentages. Continuous parameters were represented by meanSD. Association of study outcome with other factors were found out by using chi square test. And fischer exact test was used instead of chi square test when expected frequencies were considerably small. A p value of <0.05 was considered to be a statistically significant result.

Differences between patients are assessed by unpaired t test and frequency of parameters by the chi square test. Linear regression analysis is used and correlation coefficients are calculated by Pearsons method.

RESULTS:

 

The study was conducted in 200 cases of myocardial infarction who were   admitted in coronary care unit . All cases met inclusion and exclusion criteria and consented to enrolment in the study. Out of the 200 patients, gender distribution in our study were 16% (n = 32) females and 84% ( n = 168) males. Among the patients, 89 had Anterior Wall Myocardial Infarction and 111 patients had Inferior wall Myocardial Infarction. The mean age of occurrence of AWMI was 53 years and IWMI was 57 years.Conventional risk factors were equally distributed in both the groups except  smoking . Smoking was more common in the IWMI.  Dyslipidemia was seen only in 10 % patients(Table.1) 

CLINICAL RV DYSFUNCTION

Clinical RV dysfunction is manifested as raised jugular venous pulse, hypotension, and tricuspid regurgitation. Clinical RV dysfunction  was seen more in patients with IWMI (Table.2)

 

TR murmur were seen in 9 patients with inferior wall MI and  3  patients with anterior wall MI. It was not statically significant.

JVP was raised in 39 patients (35.1%) with IWMI and 7 patients (7.9%) with AWMI. It was statistically significant (p = 0.0001) means that, clinically RV dysfunction is seen more in IWMI.

TAPSE v/s SITE OF MI

Chi square value:0.342 ; P value:0.559

 

TAPSE has significant prognostic value for predicting early cardiac events. It is a measure of global right ventricular function. When TAPSE less than 16mm is taken as abnormal.3, 30.3% (n= 27) had abnormal TAPSE in AWMI and 34.2% (n = 38) in IWMI( Table.3). According to Fisher Exact test, The prevalence of RV dysfunction is comparable in both AWMI and IWMI Since p value not significant. (>0.05)

This indirectly says that in our study we had almost comparable RV involvement in both IWMI and AWMI.

TISSUE DOPPLER MPI v/s SITE OF MI

 

In our study, Tissue Doppler MPI value more than 0.55 was seen in 34 patients (38.2%) with Anterior Wall MI and 55 patients (49.5%) with inferior wall MI      (Table.4). This global RV function  marker was also seen impaired   in both  anterior and inferior  wall MI in more than one third of patients..

 

 

RV DIASTOLIC DYSFUNCTION :

DIASTOLIC DYSFUNCTION v/s SITE OF MI

Out of 89 patients, 96.6% (n = 86) patients who had anterior wall MI had RV diastolic dysfunction. Meanwhile , 97.3% patients with (n = 108) inferior wall MI also  had diastolic dysfunction(Table 5). According to Fisher Exact test, the prevalence of  RV diastolic dysfunction is comparable in both AWMI and IWMI, since p value not significant (>0.05) .This  implies that both anterior wall and inferior wall MI had significant RV diastolic dysfunction.

 

Our study shows that LV ejection less than 40% was more commonly  seen  in 84.3  % in  AWMI { n = 75 }  while in patients with IWMI, LV ejection fraction is maintained in majority of the patients. (LVEF < 40 % in 18.9% { n = 21}). The statistical difference was  significant.

 

 

DISCUSSION:

Our study tried to compare the right ventricular involvement in both anterior and inferior wall MI by analyzing the clinical, echocardiographic profile of 200 patients with myocardial infarction during the period of Dec 2012 to Dec 2013. Age, gender distribution, risk factors, clinical findings, echocardiographic and angiogram findings including ECG, TAPSE, Tissue Doppler MPI, ejection fraction were compared with various studies published in the literature.

Clinical description of right ventricular myocardial infarction was first given by Saunders in 1930 when he reported a case with triad of hypotension, elevated jugular veins, and clear lung fields and extensive RV necrosis in autopsy.1 The incidence of RVMI in inferior wall MI varies from 20% to 50% in various studies, and in less than 10% of patients RVMI is hemodynamically significant.2 Post-mortem studies mention RV involvement after left ventricular infarction4. Abbate et al. found RV cardiomyocyte apoptosis in patients with anteroseptal myocardial infarction and RV-free wall involvement upon histopathological examination5. Bodi et al. showed RV involvement after Anterior wall MI in an animal model with MRI6. Jensen et al. revealed RV involvement after anterior wall STEMI in a patient with MRI, and they found that delayed RV enhancement in anterior wall ST-segment elevation MI is associated with a worse prognosis7

 

In this series, a significant number of patient (26%) were less than 50 years of age, showing the early onset of the disease. It also highlights the importance of screening of high risk young patients as shown by other studies 8,9.

A study conducted by Multani AS et al10 showed mean age of MI as 54. In which 72% (n=36) were males and 28% (n=14) were females. Its also note worthy that Indians are affected a decade earlier than the westners. There is general agreement that coronary artery disease is multifactorial in aetiology. Multiple risk factors co-existed in causing the MI of which, smoking, hypertension, alcoholism and diabetes mellitus were more common. There were no statistical significance in the occurrence of MI and risk factors between the two groups of  MI  except smoking.half of inferior wall MI patients were smokers.

 

Diabetes mellitus was present in 48%  of patients, anterior wall MI patients 48(53.9%) and inferior wall MI patients 47(42.3%) (P value = 0.103).

Hypercholesterolemia was seen only in 21 out of 200(10.5%) patients , seven patients with AWMI (7.9%) and fourteen patients with IWMI (12.6%).

These finding  implies that, we have to take in account non-lipid factors which contribute in the genesis of atherosclerosis and thereby coronary occlusion.

 

The most important markers of RV dysfunction are raised JVP, Kussmauls sign, RV S3 and tricuspid regurgitation murmur.

It is known that elevated JVP may suggest right ventricular involvement in patients with inferior MI. These results were supported by Mittal et al.13 who reported that raised jugular venous pressure had high specificity (96.8%) but low sensitivity (39%) in diagnosing RV infarction.

Jugular venous pressure was raised in 35.1% patients with IWMI and 7.9% with AWMI. (P< 0.01). Croft et al found a raised jugular venous pressure in 45% of patients with right ventricular infarction in their study. In none of these patients, there were signs of left ventricular failure, pulmonary disease or pericardial effusion. Experimental necrosis of the right ventricle has been shown to decrease the ability of the right ventricle to handle a volume load. Any maneuver that stress the right ventricle would help uncover subclinical dysfunction. This is best done at bed side by observing for a Kussmauls sign. This physiological response is altered in right ventricular infarction and may be the earliest hemodynamic change in right ventricular infarction which produces a Kussmauls sign.

Twelve patients in present study had tricuspid regurgitation which may complicate right ventricular infarction. Right ventricular S3 was also seen in 6 patients (6.7%) with anterior wall MI and 32 patients (28.8%) with inferior wall MI.  The reduced incidence of clinical manifestation of  RVdysfunction in anterior wall MI patients may be due to diuretic usage and  cautious fluid balance for LV dysfunction in these patients.

Global assessment of RV function includes the myocardial performance index (MPI), RV dP/dt, RV EF, and FAC . Regional approaches include tissue Dopplerderived and 2D strain, Doppler derived systolic velocities of the annulus (S), and TAPSE.

 

Tricuspid annular plane systolic excursion (TAPSE) is a well-known echocardiographic parameter for assessment of function of right ventricle. TAPSE < 16 mm indicates RV systolic dysfunction. Although it measures longitudinal function, it has shown good correlation with techniques estimating RV global systolic function.

Hayrapetyan et al showed that , TAPSE has significant prognostic value for predicting early cardiac events, including death and life-threatening cardiac complications following acute inferior STEMI because of right ventricular infarction.14 52 % of the patients with IWMI had abnormal TAPSE in their study.

 

In our study 30.3% (n= 27) had abnormal TAPSE in AWMI and 34.2% (n = 38) in IWMI when TAPSE less than 16mm is taken as abnormal.15 The incidence of less abnormal patients may be due to stricter low reference values taken in our study according to the ASE guidelines.

According to Fisher Exact test, the prevalence of RV dysfunction was comparable in both AWMI and IWMI ,since p value was  not significant (>0.05) . Studies by Bayata et al16and Mehmet et al 17 also proved the same.

ASE guidelines suggest a tissue Doppler systolic velocity ≤10 cm/s and MPI-TDI ≥ 0.55 as indicative of RV systolic dysfunction. Tissue Doppler systolic annular velocity and MPI has also been shown to correlate with prognosis in IWMI18 and also with radionuclide derived RVEF in earlier studies. 19

Karkouros et al20 noted that  RV-MPI was significantly higher in patients with RV-MI compared to patients without RV-MI and controls.

In our study, Tissue Doppler MPI value more than 0.55 was seen in 34 patients (38.2%) with Anterior Wall MI and 55 patients (49.5%) with inferior wall MI( P value:0.109). According to Fisher Exact test, the prevalence of RV dysfunction is comparable in both AWMI and IWMI,  since p value is not significant (>0.05).

Out of 89 patients, 96.6% (n = 86) patients who had anterior wall MI had RV diastolic dysfunction. Meanwhile, 97.3% patients with (n = 108) inferior wall MI had diastolic dysfunction.

According to Fisher Exact test, the prevalence of  RV diastolic dysfunction is comparable in both AWMI and IWMI as p value not significant (>0.05).

This indirectly implies that both anterior wall and inferior wall MI had significant  RV diastolic dysfunction.

 

 

 

 

CONCLUSION

RV dysfunction is present in one third of patients with acute myocardial infarction irrespective of site of MI. Unlike to the previous assumption that RV dysfunction is seen mainly in acute inferior wall MI, our study shows equal prevalence. RV diastolic dysfunction is also seen in more than 90% of the patients with acute myocardial infarction. The clinical and echocardiographic discordance in RV dysfunction between IWMI and AWMI may be due to the fact that the more use of diuretics in AWMI along with the pliable infarcted septum is less affecting the RV filling pressures than a thick normal septum of Inferior wall MI.  Routine assessment of the RV function along with LV ejection fraction in Echocardiogram assessment of acute MI patients will gives better insight in fluid, drug management and prognosis of acute MI patients.

 

 

 

 

 

 

 

 

 

 

ACKNOWLEDGEMENT: We acknowledge the help of   Dr jayakumar T G,Dr Rajesh G,Dr Geofi George for valuable suggestions and  Mrs Neelima Mansoor for her technical assistance.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                                  BIBLIOGRAPHY

 

  1. Guiha NH, Limas CJ, Cohn JN.Predominant RV dysfunction after experimental RV destruction. Am J Cardiol 1974; 33:254.
  2. Cohn JN, Guiha NH, Broder MI, LimasY.Right ventricular infarction, clinical and hemodynamic features. Am J Cardiol 197; 33:209-214.
  3.  Chou TC, Bel VD, Khan J, Allen J, Brockmeier L, Fowler NO. Electrocardiographic diagnosis of right ventricular infarction. Am J Med 1981;70:1175-1180
  4.  Morgera T, Alberti E, Silvestri F, Pandullo C, Della mea MT, Camerini F. Right precordial ST and QRS changes in the diagnosis of right ventricular infarction.Am Heart J 1984; 108:13-18.
  5. Standring S, Johnson D, Shah P. Heart and Great vessels.GraysAnatomy.The anatomical basis of clinical practice 39th edition. Elsevier Churchill Livingstone 2005; 997-101
  6.  Forman MB, Goodin J, Phelan B, Kopelman H, Virmani R. Electrocardiographic changes associated with isolated right ventricular infarction. J Am CollCardiol 1984;4:640-3.
  7. Weyman A. Practices and principles of echocardiography. 2nd ed. Philadelphia: Lippincott, Williams and Wilkins; 1994. 
  8. Kaul U, Dogra B, Manchanda SC et al. Myocardial infarction in young Indian patients: Risk factors and coronary arteriographic profile. Am H J 1998; 112 (1): 71-5.
  9. Uhl GS, Farrell PW. Myocardial infraction in young adults: Risk factors and natural history. Am H J 1983; 105: 584. 
  10. Multani AS, Neki NS, Khurana A, Sikri T. Clinical and electrocardiographic profile of RVI in acute inferior wall myocardial infarction.JAPI Jan 2001; vol 49:182. 
  11. Sharma C, Nagpal GS, Nagpal HK. Clinical and angiographic profile of coronary artery disease in Western Punjab. Indian Heart J 2005; 57:543-554. 
  12. Kanitz MG, Giovannucci SJ, Jones JS, Mott M. Myocardial infarction in young adults: Risks factors and clinical features. Journal of Emergency Med  1999;14:139-145. 
  13. S.R. Mittal, S. Garg, M. Lalgarhia . Jugular venous pressure and pulse wave form in the diagnosis of right ventricular infarction Int J Cardiol, 53 (3) (1996), pp. 253256 
  14. H.G. Hayrapetyan , K.G. Adamyan ,Erebouni MC, Yerevan, Armenia; Instituteof Cardiology, Yerevan, Armenia. Prognostic usefulness of the tricuspid annular plane systolic excursion in patients with acute inferior myocardial infarction.
  15. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography. J Am SocEchocardiogr 2010;23:685-713.
  16. SerdarBayata, EypAvcı, Murat Yeşil, ErdinArıkan, NursenPostacı, SelcenYakarTlce. Clinic of 1st Cardiology, Atatrk Education and Research Hospital, İzmir-Turkey ; Tricuspid annular motion in right coronary artery-related acute inferior myocardial infarction with or without right ventricular involvement
  17. Mehmet Ata Akl ,FarukErta, Hasan Kaya, Mehmet ZihniBilik ; Comparison of right ventricular functions according to infarct localization using advanced echocardiographic methods in myocardial infarction with ST elevation. Dicle Medical Journal 2012; 39 (4): 561-566
  18. Dokainish H., Abbey H., Gin K. Usefulness of tissue Doppler imaging in the diagnosis and prognosis of acute right ventricular infarction with inferior wall acute left ventricular infarction.Am J Cardiol. 2005;95:10391042. 
  19. Karnati P.K., El-Hajjar M., Torosoff M. Myocardial performance index correlates with right ventricular ejection fraction measured by nuclear ventriculography. Echocardiography. 2008;25:381385
  20. N. Kakouros, S. Kakouros, J. Lekakis, I. Rizos, D. Cokkinos. Tissue Doppler imaging of the tricuspid annulus and myocardial performance index in the evaluation of right ventricular involvement in the acute and late phase of a first inferior myocardial infarction. Echocardiography, 28 (3) (2011), pp. 311319
  21. Gulati VK, Katz WE, Follansbee WP, Gorcsan J III. Mitral annular descent velocity by tissue Doppler echocardiography as an index of global left ventricular function.  Am J Cardiol 1996;77:979-84. 
  22. Monika Garg, Akash Deep Aggarwal, SantPrakashKataria ; Coronary Atherosclerosis and Myocardial Infarction An Autopsy Study . J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33. 
  23. Yazdi SAT, Rezaei A, Azari JB, Hejazi A, Shakeri MT, Shahri MK. Prevalence of Atherosclerotic Plaques in Autopsy Cases with Noncardiac Death. Iranian J Pathol 2009;4(3):101-104.
  24. Farb A, Tang AL, Burke AP, Sessums L, Liang Y, Virmani R. Sudden coronary death Frequency of active coronary lesions, inactive coronary lesions and myocardial infarction. Circulation 1995;92:1701-9. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Refbacks

  • There are currently no refbacks.