|Year : 2020 | Volume
| Issue : 1 | Page : 48-54
Assessment of right ventricular functions by echocardiography in patients with acute myocardial infarction in North India: An observational study
Hakim Irfan Showkat1, Sadaf Anwar1, LC Gupta1, Rekha Mishra1, S Padmawati1, Arif Sarmast2, Basharat Mujtaba2, Vinod Sharma1, Siddharth Saxena3, Sudheer Saxena4
1 Department of Cardiology, National Heart Institute, New Delhi, India
2 Department of Surgery, SKIMS, Srinagar, Jammu and Kashmir, India
3 Kingsbrook Jewish Medical Center, New York, USA
4 Max Mohali, Punjab, India
|Date of Submission||29-Sep-2019|
|Date of Decision||13-Dec-2019|
|Date of Acceptance||27-Dec-2019|
|Date of Web Publication||30-Jun-2020|
Dr. Hakim Irfan Showkat
Department of Cardiology, National Heart Institute, East of Kailash, New Delhi - 110 065
Source of Support: None, Conflict of Interest: None
Background: Right Ventricle (RV) dysfunction may be primarily attributed to abnormality of RV myocardium or secondary to left ventricle (LV) dysfunction, as a consequence of “Ventricular Interdependence” between the two ventricles, as they are encircled by common muscle fibres, share a common septal wall and are enclosed within a common pericardium6,7 Early recognition of RV dysfunction is warranted but till today it remains a challenging task because of complex structure and asymmetric.
Aims: To study Right Ventricular functions in Acute coronary syndrome.
Method: All patients with first presentation of Acute STEMI/NSTEMI with a total of 100 patients who match our inclusion criteria were studied from June 2015 to May 2017 on Phillips Epiq 7 echocardiography Machine with follow up echocardiography at discharge.
Results: A total of 100 patients of acute myocardial infarction were studied with 73% STEMI & 27% NSTEMI & among these 68% were anterior wall MI (AWMI) & 32% inferior wal MI (IWMI). Prevalence of different risk factors observed in study population was as follows: Dyslipidaemia in 68% patients, diabetes mellitus 64%, hypertension was present in 54%, Family history of coronary artery disease (CAD) was present in 43 % of patients & Smoking was prevalent in 27 % of cases. The present study demonstrated presence of RV dysfunction assessed by echocardiography, in acute MI (STEMI/NSTEMI) irrespective of infarction location and was more commonly seen in AWMI than IWMI.
Conclusions: The present study demonstrates presence of RV dysfunction assessed by echocardiography (RVEDD (RV end diastolic diameter), TAPSE (transannular plane systolic excursion), FAC (Fractional area change), E/E', RV MPI (Myocardial performance index) by TDI (tissue Doppler imaging)), in acute MI (STEMI/NSTEMI) irrespective of infarction location and was more commonly seen in AWMI than IWMI. This study demonstrated presence of RV dysfunction in acute MI more so in STEMI than NSTEMI with high morbidity and mortality in patients with RV dysfunction irrespective of site of infarction.
Keywords: Acute coronary syndrome, myocardial infarction, right ventricle
|How to cite this article:|
Showkat HI, Anwar S, Gupta L C, Mishra R, Padmawati S, Sarmast A, Mujtaba B, Sharma V, Saxena S, Saxena S. Assessment of right ventricular functions by echocardiography in patients with acute myocardial infarction in North India: An observational study. Nig J Cardiol 2020;17:48-54
|How to cite this URL:|
Showkat HI, Anwar S, Gupta L C, Mishra R, Padmawati S, Sarmast A, Mujtaba B, Sharma V, Saxena S, Saxena S. Assessment of right ventricular functions by echocardiography in patients with acute myocardial infarction in North India: An observational study. Nig J Cardiol [serial online] 2020 [cited 2021 Apr 18];17:48-54. Available from: https://www.nigjcardiol.org/text.asp?2020/17/1/48/288645
| Introduction|| |
The right ventricle (RV) differs from the left ventricle (LV) in many anatomic and physiologic aspects. The RV is a pyramidal-shaped chamber, comprised of the RV free wall (RVFW) and the interventricular septum. RV systolic pressure and flow are generated by RVFW shortening and contraction in a peristaltic wave towards the septum from apex to outflow tract. Interventricular septal contraction further contributes to RV performance. The RVFW is a thin structure with a small tissue mass generating low pressures, and with relatively low oxygenation demands. The RV has an extensive collateral coronary circulation from the left coronary artery and in the absence of significant RV hypertrophy, receives coronary perfusion during both systole and diastole. Consequently, the RV has more favorable oxygenation supply-demand characteristics and is relatively resistant to ischemia when compared to the LV. This disparity renders the RV less vulnerable to ischemia and less susceptible to myocardial injury when right coronary artery occlusion occurs compared with the extent of left ventricular dysfunction during left coronary artery occlusion., RV involvement identified by echocardiography is associated with worse prognosis in patients with acute myocardial infarction (MI). RV dysfunction may be primarily attributed to abnormality of RV myocardium or secondary to LV dysfunction, as a consequence of “Ventricular Interdependence” between the two ventricles, as they are encircled by common muscle fibers, share a common septal wall, and are enclosed within a common pericardium., Early recognition of RV dysfunction is warranted; but, till today, it remains a challenging task because of complex structure and asymmetric shape of RV.
| Materials and Methods|| |
A prospective observational study entitled “Assessment of RV functions in patients with acute MI-An observational study” was conducted from June 2015 to May 2017 in the Department of Cardiology, National Heart Institute, New Delhi, which is a 100-bedded state of art cardiology center staffed by full-time cardiology team with supportive critical team staff.
The study was conducted after approval from local ethical committee after securing informed consent from patients or attendants for participation in the study.
A total of 100 patients who match our inclusion criteria were studied from June 2015 to May 2017. The procedure was explained to each participants of the study and written informed consent was obtained. Patients were recruited only after written informed consent.
Inclusion criteria for the study subjects
All patients with first presentation of:
- Acute ST-elevation MI (STEMI)/non-STEMI (NSTEMI).
- Any associated RV infarction by electrocardiogram (ECG) and echocardiography
- Atrial fibrillation or flutter, bundle branch block, or any other intraventricular conduction delay
- Renal failure (acute or chronic)
- Previous MI or coronary artery bypass graft (CABG) surgery
- Congenital Heart disease or pericardial disease
- Severe valvular heart disease
- Chronic obstructive lung disease, cor pulmonale, and obstructive sleep apnea and
- Strong clinical suspicion of pulmonary embolism.
All patients after proper history were admitted in intensive cardiac care unit (ICCU) with proper informed consent taken and subjected to evaluation and management:
- Hemogram, renal function, lipid profile, X-ray imaging
- Cardiac enzymes (Trop-T, creatine phosphokinase (CPK), CPK-MB)
- Echocardiography at presentation and at discharge.
Patients were revaluated at the time of discharge for RV functions as on presentation by echocardiography.
Study was performed on-echocardiography equipment Phillips CX-50 with Doppler tissue imaging (DTI) technology, S 5-1 MHz phased array transducer with operating frequency 2–4MHz. Sample volume of 2–4 mm was used. Nyquist limit set at 20–60 cm/s was used.
Evaluation of right ventricle functions included
Tricuspid annular plane systolic excursion (TAPSE) for ejection fraction: TAPSE measurement is devoid of geometrical assumptions or traceable endocardial outlines, is easy to measure, reproducible, and feasible, has a very good correlation with RV systolic function, and is recognized as an important tool for assessing RV systolic function.
Fractional area change (FAC) is defined as (RV end diastolic area-RV end systolic area)/RV end diastolic area × 100. Two-dimensional (2D) FAC (as a percentage) provides an estimate of RV systolic function. 2D FAC <35% indicates RV systolic dysfunction.
DTI-RV Myocardial Performance Index (MPI) (RV-Tei Index), the most reliable and reproducibly imaged regions of the RV is the tricuspid annulus and the basal free wall segment. These regions were assessed by pulsed tissue Doppler and color-coded tissue Doppler to measure the longitudinal velocity of excursion. DTI is an index of RV systolic and diastolic functions. The easiest method to assess the Tei index is a tissue Doppler signal of the RV in apical 4-chamber view. The tissue Doppler method allows for measurement of the Tei index or MPI as well as S', E', and A', all from a single image.
TEI index (RV MPI) = IVCT + IVRT/RVET = TCOT-RVET/RVET
(IVCT = Isovolumic contraction time, IVRT = Isovolumic relaxation time, TCOT: Tricuspid opening time, RVET = RV ejection time) [Table 1]
|Table 1: Baseline characteristics, risk factors, enzymes and angiographic distribution in anterior wall myocardial infarction and inferior wall myocardial infarction|
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Transtricuspid E/E' was assessed in all patients in apical 4 chamber view. Although preload-dependent, the tricuspid E/E' ratio is a good marker of RV diastolic dysfunction. Ratio of >6 was considered abnormal as per guidelines.
RV end diastolic diameter (RVEDD) was taken in apical 4 chamber view and was considered abnormal if >33 mm in mid RV wall as per guidelines.
LV ejection fraction (LVEF) was assessed by modified Simpsons biplane method in apical 4 chamber view and considered abnormal if <50% [Table 2].
The final data were recorded on a predesigned study pro forma and was managed in Microsoft Excel. Continuous data are presented as mean ± standard deviation and categorical data are presented as frequencies and percentages. Differences in characteristics between patient groups were evaluated using the unpaired Student's t-test and Chi-square test [Table 3] and [Graph 1]. The minimum significance level (*P value) was set at 0.05.
| Results and Observations|| |
A total of 100 patients were included in the study after written informed consent. Exclusion criteria were applied as per protocol. Complete clinical, biochemical and echocardiographic measurements were carried out. Complete data of 100 patients (67 male and 33 female) were available for final analysis. The results and observations are as under.
Anterior wall MI (AWMI) was more common in males, while diabetes mellitus(DM) was seen almost equal in AWMI (45.3) and inferior wall MI (IWMI) (54.7). Hypertension (HTN) & dyslipidemia was common in AWMI. Family history of coronary artery disease (CAD) was equally distributed in AWMI and IWMI. Cardiac Enzymes were raised quantitaively more in AMWI.
Chest pain was the most common symptom seen in 56.2% of STEMI and 55.5% in NSTEMI patients followed by dyspnea in 20.5% and 18.5% respectively, Arrhythmias were seen in about 4% of patients and shock was least common presentation in around 3% of patients. Risk factors seen were DM in 64% of patients and HTN in 54%, dyslipidemia in 68% followed by family history of CAD in 43% and smoking was seen in 27% of patients. AWMI was more common 68% than IWMI 32%. STEMI was seen in 73% patients compared to NSTEMI in 27% of patients.
RV functional abnormalities by echocardiographic parameters included mid RVEDD >33 mm in 45%, TAPSE <17 mm in 57%, FAC <35 in 42%, E/E' >6 in 53%, RV MPI > 0.55 in 59% and LVEF <50% in 77% of patients at presentation. At discharge (mean days ±5), mid RVEDD >33 mm was seen in 41%, TAPSE <17 mm in 43%, FAC <35 in 39%, E/E' >6 in 38%, RV MPI > 0.55 in 51%, and LVEF <50% in 63% of patients [Table 1].
Most common treatment option utilized was percutaneous coronary intervention (PCI) following thrombolysis in 53% followed by primary PCI in 24% and least common was CABG in 5% of patients. Patients who received only Thrombolysis were 18% (of which 4 patients had recanalized artery postthrombolysis with no significant coronary stenosis). 14% patients post thrombolysis who did not give consent for PCI or CABG in present admission were discharged in stable condition [Table 4].
|Table 4: Treatment options used were primary percutaneous coronary intervention|
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At presentation when RV functions were compared in AWMI versus IWMI, abnormal values for RVEDD was seen in 64.4% AWMI versus 35.6% in IWMI and at discharge in 63.4% and 36.6% patients respectively with no statistical significance. TAPSE <17 mm was seen in 66.6% of AWMI and in 33.4% of IWMI at presentation and at discharge in 67.4% and 32.6% respectively with no statistical significant change. FAC at presentation was abnormal in 57% in AWMI and 43% in IWMI and at discharge no statistical significant change was seen. E/E' was abnormal in 79% patients in AWMI compared to 21% in IWMI and there was a significant change at discharge with abnormal E/E' in 76% in AWMI versus 24% in IWMI. 14% patients who received only thrombolysis with no consent for definitive treatment (PCI or CABG) had least improvement in RV function at discharge [Table 5].
|Table 5: Echo parameters at presentation and discharge in anterior wall myocardial infarction and inferior wall myocardial infarction|
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At presentation when RV functions were compared in STEMI versus NSTEMI, abnormal values for RVEDD was seen in 73.3% versus 26.7% in IWMI and at discharge in STEMI seen in 53.3% and in 46.7% in IWMI with no statistical significance. TAPSE <17 mm was seen 84.2% of STEMI and in 15.8% of NSTEMI at presentation and at discharge in 72% of STEMI versus 18% in IWMI with no statistical significant change. FAC at presentation was abnormal in 85.7% in STEMI and 14.3% in NSTEMI and at discharge statistical significant change was seen with only 52.6% abnormal FAC in STEMI and 47.4% in NSTEMI. E/E' was abnormal in 67.9% patients in STEMI compared to 32.1% in NSTEMI, and there was a significant change at discharge with abnormal E/E' in 61.5% in STEMI versus 38.5% in NSTEMI. Abnormal RV MPI at presentation was seen in 72.9% of STEMI and 27.1% of NSTEMI patients with no statistical change at discharge. 14% patients who received only thrombolysis with no consent for definitive treatment (PCI or CABG) had least improvement in RV function at discharge [Table 6].
|Table 6: Echo parameters at presentation and discharge in ST-elevation myocardial infarction versus non-ST-elevation myocardial infarction|
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| Discussion|| |
Acute MI involving only the RV is an uncommon event. More often, RV MI (RVMI) is associated with acute STEMI of the inferior wall of the LV, and occurs in 30%–50% of such cases.
RVMI is associated with higher in-hospital morbidity and mortality compared with patients with a similar infarction territory in the LV but that does not involve the RV. However, long-term prognosis is generally good for those who survive the event.
The present study of 100 cases from our institute for last 2 years from June 2015 to May 2017 is based on study about to investigate the effect of different infarction sites on RV functional changes in patients with a first acute MI without concomitant RV infarction. The comparison of RV functions in STEMI versus NSTEMI is made. The clinicopathological vis a vis imaging in the form of ECG and echocardiography was also studied. The troponin assay is done in all cases as well. The analyzed data from the results and observations of this study were compared with the previous studies.
In this study, the age of the patients ranged from 20 years to 80 years. The youngest patient being 21 years where as the oldest patient was of 80 years old. Patients who were below 40 years of age were (10%). Majority of patients (69%) were middle aged and elderly (>50 years). Whereas, females were 33% with a male:female ratio of 2.03:1.
In our study the risk factors were observed which included dyslipidemia in 68%, DM in 64%, HTN 54%, family history of CAD 43%, and smoking 27% of patients. Dyslipidemia was found as the most common risk factor 68%, while as family history was found in 43%. The other risk factors were seen equally, just about 50% of cases. Smoking was seen least commonly in 27% of patients. Agarwal et al. studied the risk of MI in young adults. Their study consisted of 50 patients (males - 30, females -20). Fasting blood glucose, fasting lipid profile, serial ECGs, and the cardiac enzymes (CPK-MB) were evaluated. The risk factors which were studied were HTN, DM, smoking habits, overweight body mass index of >25 kg/m2, hyperlipidaemia (serum cholesterol of 200 mg%), a past history of ischemic heart disease (IHD), and a family history of ischemic heart disease. In our study, the most common presentation was chest pain in both STEMI as well as NSTEMI. It was followed by dyspnea and angina equivalents. Least common presentation was shock.
RV function was assessed in both AWSTEMI and IWSTEMI. In our study, 73% patients were in STEMI class of which 68% were AWMI and rest were IWMI. Clinical parameters of all patients and their hemodynamic stability at admission were assessed. All patients were subjected to intervention and their outcome compared on discharge. Adilakshmi and Pakira studied the RV function in anterior and inferior STEMI. The study group comprised 100 Anterior wall STEMI and 50 Inferior wall STEMI patients having history of characteristic ischemic chest pain (>30 min), ECG suggestive of STEMI and positive serum cardiac markers (CPKMB, TroponinT) for myocardial necrosis. They concluded that RV Function can be affected not only in IWSTEMI but also in AWSTEMI. In our study, we found that RVEDD was abnormal in 43% of patients of acute MI without RV infarction. Firoozeh et al. similar to our results found RVEDD increased in both AWMI as well as IWMI in almost similar frequency. TAPSE or tricuspid annular motion (TAM) is a method to measure the distance of systolic excursion of the RV annular segment along its longitudinal plane, from a standard apical 4-chamber window. TAPSE or TAM represents longitudinal systolic function of the RV. It is inferred that the greater the descent of the base in systole, the better the RV systolic function. TAPSE was found abnormal in total of 57% cases whereas RV-MPI was found abnormal in 59% of total patients in the study. The other two parameters, FAC and RVEDD were observed in normal limits in around 50% patients. E/E' was abnormal in 53% cases and this was found more in AWMI patients than in IWMI. B Adilakshmi and Pakira revealed that, systolic TAPSE/TAM was significantly lower in patients with inferior MI (20.5 ± 5 mm) as well as anterior MI (23 ±4 mm) compared with healthy controls (27 ±4 mm, P < 0.001), respectively; the TAPSE/TAM was significantly lower in patients with RV infarction. Jesper et al. studied the TAPSE as predictor of heart failure. In their study TAPSE were correlated with global and regional measures of longitudinal LV function, segmental wall motion scores and measures of diastolic LV function as measured from transthoracic echocardiography.
Roopesh et al. found the prevalence of RV dysfunction in echo cardiogram was comparable in both AWMI and IWMI. In this study 30.3% (n = 27) had abnormal TAPSE in AWMI and 34.2% (n = 38) in IWMI. Louisa Antoni et al. studied the prognostic value of RV function in patients with acute MI treated with primary PCI. RV-FAC was abnormal in 42% of patients and it was more commonly seen in AWMI than IWMI. Similar to our study B Adilakshmi and Pakira found the parameter of echocardiography RV-FAC was abnormal more in AWMI than IWMI. Louisa Antoni et al. in his study found that RVFAC was strong predictor of the composite end point all-cause mortality, reinfarction, and hospitalization for heart failure. Firoozehet al. found in their study that E/E' >6 was seen in 77% and 56% of the patients with anterior and inferior MI, respectively. In our study RV MPI TDI (Tei Index) was abnormal in 59% of patient and was more common in AWMI than IWMI. Firoozehet al. also showed abnormal Tei index in AWMI. Møller et al.et al. demonstrated that an abnormal RV Tei index was present in 80% of patients with MI. Ozturk et al. also found a significant increase in this index after anterior STEMI. In that study, the alteration of RV Tei index was more pronounced in patients with anterior MI. Similar to our study, the findings of the study by Hsu et al. revealed that RV Tei index was significantly higher in anterior MI than in inferior MI. All the patients were subjected to coronary angiography in this study. The involvement of double vessels (left anterior descending [LAD] and left circumflex artery [LCX] or LAD and Right coronary artery [RCA] or LCX and RCA or any combination of two major vessels) was the most common pathology (32%) followed by LAD vessel involvement (26%) and the right coronary artery being the least (16%). The comparison vis a vis AWMI and IWMI was also made in terms of vascular involvement. It was found that DVD and LAD are commonly occluded in AWMI whereas RCA was the main involved vessel in IWMI. Bhawani et al. in 2016 studied the pattern of coronary artery involvement in patients with acute coronary syndrome (ACS-STEMI).
In our study, treatment options used were either primary PCI, thrombolysis (either tenecteplase or reteplase), PCI after thrombolysis or CABG. Most common treatment option utilized was PCI following thrombolysis in 53% followed by primary PCI in 24% and least common was CABG in 5% of patients.
Global RV performance recovers within days, regardless of the patency status of the infarct related artery. Even in chronic right coronary artery occlusion global RV performance improves greatly as early as postinfarction day 5, despite persistent severe RV free wall dysfunction. Reperfusion facilitates recovery of RV function and minimizes the extent of infarction even after prolonged ischemia. Our study also showed some improvement of RV functions at the time of discharge with mean time of ±5 days. Maximum change was seen in TAPSE followed by E/E' with least improvement in FAC. B A Popescu in their study showed RV functional recovery at the discharge time and also at the 6-month follow-up. Ilker et al. found that there was no difference between the groups with regard to mean RV-FAC values obtained before PCI and at the 1-month follow-up. Mean RV-FAC values observed at the 1-month follow-up were significantly increased within each group compared to the pre-PCI period. Karakurt and Akdemir found patients who were managed with primary PCI following nonanterior STEMI were compared to those who received thrombolysis alone, and similar mean RV-MPIs were observed in both groups at 72 h after the infarction.
This study was carried out in hospital population with coronary heart diseases, where the prevalence of risk factors is expected to be higher than general population, which limits the generalizability of our findings for risk factors. Our study population had only 100 patients which is a small number; this was because we followed rigid criteria to exclude common comorbid disease. Extent of infarction, contractile reserve, and collateral supply could vary from patient to patient. We assessed RV functions by 2D echocardiography/Doppler study with no comparison by cardiac magnetic resonance imaging which is a better modality and gold standard for evaluation of RV functions. As pointed out in the limitations, the findings are in a small number of individuals and limited to inhospital patients so findings need to be reconfirmed with larger numbers.
| Conclusion|| |
The present study demonstrates presence of RV dysfunction assessed by echocardiography (RVEDD (RV end diastolic diameter), TAPSE (transannular plane systolic excursion), FAC (Fractional area change), E/E', RV MPI (Myocardial performance index) by TDI (tissue Doppler imaging)), in acute MI (STEMI/NSTEMI) irrespective of infarction location and was more commonly seen in AWMI than IWMI. This study demonstrated presence of RV dysfunction in acute MI more so in STEMI than NSTEMI with high morbidity and mortality in patients with RV dysfunction irrespective of site of infarction.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]