European Journal of Cardiovascular Medicine

Cardiovascular diseases (CVD) are the leading cause of death and disability in the world [1,2]. It was responsible for 31.8% of all deaths and 14.7% of Disability Adjusted Life Years (DALYs) globally in the year 2017[2]. Prevalence of Anterior wall MI (AWMI) (55%) is the more than inferior wall MI (IWMI) (40-50%)[3]. Inferior wall myocardial infarction (IWMI) have more favorable prognosis than anterior wall MI [4]. It has also been shown that right ventricular infarction occurs exclusively in association with inferior wall myocardial infarction or inferoposterior myocardial infarction[5]. Incidence of Right ventricular infarction (RVI) in inferior wall MI (IWMI) is 25-50%[6]. RVMI increases incidence of cardiogenic shock, Conduction abnormalities, complete heart block, RV rupture, cardiac tamponade, pulmonary embolism, atrial fibrillation [7,8]. Barrillon et al. in 1974 Patients with right precordial ST segment elevation during inferior wall myocardial infarction were at least threefold more likely develop second or third degree heart block than patients without ST elevation [9]. Multiple risk factors are implicated, ranging from Tobacco use, cigarette smoking, hypertension, diabetes mellitus, obesity & various psychosocial stresses imposed by social dynamics and urbanization[10].

Thus the present study deals with clinical profile, risk factors, complications & mortality in acute inferior wall myocardial infarction with special emphasis on right ventricular infarction & its complications.

OBJECTIVES OF THE STUDY

The aim of this study was to study the clinical profile, prevalence of risk factors, complications & mortality in patients with acute inferior wall MI. Also comparison of various conduction abnormalities incidence & mortality between Inferior wall MI & right ventricular infarction (RVI).

One hundred patients of acute inferior wall myocardial infarction admitted in Cardiac Intensive Care Unit (CICU) at tertiary care center in PIMSR, Islampur between January 2023 to December 2024 were included in the present study.

The inclusion criteria was all patients with 12 lead ECG evidence (Leads II, III, AVF, RV2, RV3, RV4) of acute inferior & right ventricular wall STEMI. Patients with Anterior wall MI were excluded.

These cases were studied for clinical features, risk factors, complications, and mortality in relation to acute inferior wall myocardial infraction & Right Ventricular Infarction. Comparison of conduction abnormalities incidence, mortality between Inferior wall MI & right ventricular infarction.

The following data was collected from patients and analyzed -

a.       General Information & cardiovascular risk factors such as - age, sex, diabetes mellitus, hypertension, smoking, alcohol, dyslipidemia, family history, postmenopausal state.

b.       Clinical features at the time of arrival to the hospital

c.        Electrocardiographic changes in the 12 lead ECG + RV2, RV3, RV4.

d.       Treatment received in the hospital.

e.        During in-hospital stay – Patients clinical course, Complications & mortality rate were evaluated.

f.        Study of various conduction abnormalities in patients were grouped in 2 groups –

Group A - Acute inferior wall myocardial infarction (AIWMI) &

Group - B having right ventricular Infarction (RVI).

100 cases of acute inferior wall myocardial infraction with or without Right ventricular infarction were studied which are admitted in I.C.U. of Prakash Institute of medical sciences & research, URUN - ISLAMPUR in between.

 These cases were studied for clinical features, risk factors, complications, A-V conduction abnormalities and mortality.

• Age incidence & mortality in AIWI -

 Cases under study were from varying age groups youngest was 29 years old and eldest was 100 years old. The mean age was 57.4 year.

Table No.1: Age incidence & mortality In AIWI-

  In present study the highest incidence was in age group 51 – 70 Yrs. - 68%. The lowest incidence was in extremes of age group i.e. Age < 30 & > 90 Yrs. 1% in each age group. Mortality was 56% in age group 51-70 yrs. Mortality rate was 22.7% in age group 51-60 yrs. & 33.3% in age group 61-70 yrs.

2) Sex - Incidence & mortality –

Table No- 2

Out of 100 cases 66 were male (66%) and 34 were females (34%). Mortality in males was 15 (22.72%) & in females it was 29.41%. Incidence Ratio of M: F is - 1.94:1 & Mortality ratio of M: F -1.5:1

3) Incidence & mortality among males and females in various age group - Total deaths 25

Table No-3

Highest incidence of 33% amongst male was in age group 51-60 yrs. while 11% was in females in each age group of 51-60 & 61-70 yrs. Mortality amongst males was highest i.e. 40% in age group 71-80 yrs. while in female it was 45.45 & 50% in age group 61-70 yrs. & 71-80 yrs. respectively.

4) Time interval between onsets of symptom’s and time of hospital admission -

Table No- 4

20% cases admitted within 4 hours,                                41% cases admitted within 4-12 hours

61% cases admitted within 12 hours,                              8% cases admitted within 12-24 hours

78% cases admitted within 24 hours,                              11% cases admitted after 48 hours

5) Incidence of time interval between admission and mortality -

Table No - 5

Mortality in present study showed out of total 25 deaths 11(44%) deaths occurred within 12 hrs & 68% within 3 days.

6) Incidence & mortality in different cardiac symptoms –

Table No-6

In present study 87% cases admitted with chest pain & 13% cases admitted without chest pain & Mortality was 22.9% (20 out of 87 cases) with chest pain group & 38.4% (5 out of 13 cases) in patients without chest pain group.

7) Risk factors - Incidence & mortality is shown in Table no – 7.

Table No-7

In present study incidence of risk factors are as follows – 35% were using Tobacco either smoking or chewing, 19% were Chronic alcoholic, 32% having Hypertension, 26% had Diabetes Mellitus & 16% were known cases of IHD.

Incidence of mortality out of 100 cases & out of 25 total deaths in our study showed Tobacco users – 22.8% & 32%, Hypertension – 21.8% & 28%, Diabetes Mellitus – 34.6% & 36%, Alcohol users – 31.5% & 24% respectively.

8) Cardiac status Incidence & mortality- After AMI the insult of myocardium was studied and tabulated as per killip’s classification as show in table no. 8

Table No-8

Class I- No Heart failure, Class II- Mild to mod. Heart failure, Class III- Pulmonary edema (LVF), Class IV- Cardiogenic Shock.

• 42% cases were normal while 58% cases had Gr II, III, and IV Killip’s cardiac status.
• Mortality rate was 75% in Killip’s class IV& 41.6% in class III.
• Out of total 25 deaths 15 deaths i.e. 60% were from Killip’s class IV.

9) Incidence and mortality in either infarction:

Table no - 9

n present study out of 100 cases in Group - B 46 had RV infarction with higher mortality rate (17 out of 46 - 36.9%) than Group - A with Inferior wall infarction (8 out of 54 - 14.81%).

10) Incidence & mortality in various cardiac Arrhythmias in IWMI (Gr. A) & RVMI (Gr.B):

Table No. 10: Incidence & mortality in various cardiac Arrhythmias in IWMI (Group A) & RVMI (Group B):

11) Incidence & mortality in individual A-V conduction defects –

During hospital stay various arrhythmias found in IWMI & RVI cases are shown in Table no – 11

Table No. 11: Incidence & mortality in various conduction defects – without & with RV Infarction:

In present study highest incidence of Ist & IInd degree heart block was found in Group A i.e IWMI while IIIrd degree heart block was found in Group – B i.e. RVI. While highest mortality in IInd & IIIrd degree heart block was found in Group B i.e. RVI.

Age- In present study the maximum number of cases of acute IWMI were from 51-60 & 61-70 years age group i.e. 44% % & 24% respectively. The youngest and oldest patients were of 29 years and 100 years age respectively. We found low incidence in extremes of age group. The mean age was 57.4 year. Delay in hospital admission, lack of prehospital coronary care, illiteracy, non-recognition or negligence of disease symptoms, poor transportation in rural area increases death rate.

Sex: In present study there were 66% males and 34% females with male to female ratio of 1.94:1. Klein H. H. et al.^[11]. In 1977-78 found M: F ratio 2.3:1 & in 1988-89 found 2.4:1. From this study it shows that males are more commonly affected than females. Cause is according to Friedberg men’s are Tobacco chewers, heavy cigarette smokers, high blood pressure, more exposed to competitive stress of industrialization and urban life. Difference in sex hormones, predominance of estrogen in female protect coronary atherosclerosis possibly through lipid metabolism and blood clotting and low estrogen in post-menopausal women increases incidence in latter age. Mortality in present study showed out of total 25 deaths 15 deaths out of 66 males (22.72%) were males & 10 deaths out of 34 (29.4%) were females with M:F ratio 1.5:1. Higher death rate in females than males with M: F death ratio of 0.7:1. Puletti M. et al. ^[12] in 1984 found M: F ratio 1:2.5. In present study age wise male & female distribution, highest incidence of 33% amongst male was in age group 51-60 yrs. while 11% was in females in each age group of 51-60 & 61-70 yrs. Mortality amongst males was highest i.e. 40% in age group 71-80 yrs. while in female it was 45.45 & 50% in age group 61-70 yrs. & 71-80 yrs. respectively.^[13]

Time interval between symptoms and arrival to hospital: In present study 5% cases were admitted within 2 hours while 56% cases were admitted within 2-12 hours & 11% cases admitted after 24 hours. Early admission of infarction patient’s may help in reduction in mortality because of early treatment of reversible but potentially lethal arrhythmias ^[14]. Mortality in present study showed out 100 patients 11% & out of total 25 deaths 44% occurred within 12 hrs, 17% & 68% within 3 days respectively. According to study done by Ball et al. (1958) death rate was 42% within 24 hrs. & 69% within first week, while Agrawal & Mishra (1978) found death rate was 50% within 24 hrs.

Symptoms in acute inferior wall myocardial Infarction: In present study 87% cases admitted with chest pain & 13% cases admitted without chest pain. 16% had vomiting, 17% had giddiness/ syncope, 16% had palpitation, 58% had sweating & 23% had breathlessness. More than 85% of patients with acute myocardial infarction present’s with chest pain & 15-20% present without chest pain ^[15] such painless infarcts are more common in diabetics due to autonomic nervous dysfunction, elderly people or when AMI follows severe shock. Painless myocardial Infarctions are dangerous because of high mortality rate as compared to AMI with chest pain. Mortality in present study showed 22.9% (20 out of 87 cases) & 38.4% (5 out of 13 cases) in patients with chest pain & without chest pain respectively. Finding by John G. Canto et al. ^[16] incidence of myocardial infarction without chest pain was 33% & had a 23.3% in-hospital mortality rate compared with 9.3% among patients with chest pain (adjusted odds ratio for mortality, 2.21 [95% confidence interval, 2.17-2.26]).

Risk factors: Tobacco, Hypertension, Diabetes mellitus and known cases of Ischemic Heart Disease forms the major risk factors for myocardial infarction. There was marked overlapping of groups of risk factor. In present study incidence of risk factors are as follows – 35% were using Tobacco either smoking or chewing, 19% were Chronic alcoholic, 32% having Hypertension, 26% had Diabetes Mellitus & 16% were known cases of IHD. Incidence of risk factors studied by Stephen Schedit ^[17] showed 25% in tobacco users, 29% were Hypertensive, 15% were DM, while Kennelly FM ^[18] found 85% using Tobacco, 11% hypertensive & 29% known IHD. The mortality rate is directly proportional to individual risk factors & it increases with combination of various risk factors. Incidence of mortality out of 100 cases & out of 25 total deaths in our study showed Tobacco users – 22.8% & 32%, Hypertension – 21.8% & 28%, Diabetes Mellitus – 34.6% & 36%, Alcohol users – 31.5% & 24% respectively.

Site of infarction: In present study out of 100 cases 46 had RV infarction with higher mortality rate (17 out of 46 - 36.9%) than Inferior wall infarction (8 out of 54 - 14.81%).

Table 12: Various studies showing incidence of IWMI with RVI:

Cardiac status: In present study cardiac status assessed as per killip’s classification showed case incidence class I - 42%, class II -26%, class III – 12% & class IV – 20% patients. Killip Thommas - 1967 ^[25] showed in his study that total incidence of the same classes of all acute myocardial infarction to be class I – 33%, class II – 38%, class III – 10% and class IV – 19%. Mortality in present study showed 19.2% in class II, 41.6% in class III, and 75% in class IV. While other groups showed mortality rate in Class IV - by Thomas Killip ^[25] - 55.1%, Michel Oliver - 1967 ^[26] while mortality in class III – by Norris R.M. 1969 [27]. Incidence & mortality in class IV (Cardiogenic shock) in Group A & B was 5/3 (60%), 15/13(86.6%) respectively suggesting higher incidence & mortality in RV infarction than IWMI

Arrhyhmias: In present study 34 cases i.e. 34% were presented with Sinus bradycardia. This finding correlates with finding of Louis & Lomberg et al. -1972, Desmond Jullean et al. 1964 [28] , Rotman M et al. – 1973[29], - 30%, 25%, 34%, respectively. This may be due to occlusion of A-V nodal artery which supplies A-V Node, also due to increased vagal tone. Low heart rate may be due to sinus bradycardia, A-V Nodal rhythm and High grade of A-V Block. Incidence & mortality in relation to bradycardia in Group A & B was 14/4 (28.57% ), 20/10(50%) respectively suggesting higher incidence & mortality in RV infarction than IWMI

Sinus tachycardia is common with anterior wall infarction than inferior wall infarction. In present study 17% cases presented with sinus Tachycardia. Finding by Desmond Jullean et al. - [28] 1964 - 41%, Jewitt et al. 1968 ^[30]. - 26.7%. Incidence of sinus bradycardia was more than sinus tachycardia i.e. 34 verses 17. Nodal/Junctional Rhythm here A-V node assumes a role of dominant pacemaker when the sinus node is depressed. In present study 20% presented with junctional rhythm. While Desmond Jullean et al., R.Moral et al. found 11 & 10% respectively. Incidence & mortality in Group A & B was 4/2 (50%), 16/4(43.7%) respectively. Ventricular tachycardia (VT) and Ventricular Fibrillation (VF) in present study was 2% & 1% respectively. Finding by Desmond Jullean et al. [28] – 4.5% & 9%, Jewitt et al. 1968 [30] - 5.3% & 9.3% respectively.

Individual conduction defects in acute inferior wall myocardial infarction & RV infarction:

Inferior wall myocardial infarctions are due to impaired blood supply to the inferior region of the heart. In 80% of patients, the inferior wall of the heart is supplied by the right coronary artery via the posterior descending artery (PDA), while in the other 20% of patients the Posterior descending artery (PDA) a branch of the circumflex artery supplies the blood. Heart block is caused by a disturbance of conduction of excitatory impulse through the bundle of his or its main branch. Right coronary artery perfuses the sinoatrial node so heart block and bradycardia may occur with occlusion of it. A high degree heart block defined as a second or third-degree block, are common with acute inferior wall MI. The amount of collateral circulation to the AV impacts the rate of heart blocks.

Comparison between our findings with others are shown in -

Table No – 13.

First degree heart block – It occurs in 4-14 % of patients with AMI admitted to CCU. It is due to prolonged atrioventricular conduction. All impulses are able to pass but there is delay in their passage due to disturbances in conduction above the bundle of His i.e. intranodal. First degree heart block seldom causes any symptoms and rarely result in any significant alternation of cardiac function. In present study first degree heart block was noted in total 21 cases (21%) (11 in Group A i.e. with IWMI & 10 in Group B i.e. with RVI) of acute inferior wall myocardial infarction with no mortality, out of which few reverted to normal & few progressed to next level.

Second degree Heart types – It present in two types - 1) Mobitz type I or wenkeback type. 2) Mobitz type II. The second degree heart block is common in posterior - inferior wall myocardial infarction ^[27]. In the present study it was noted in total 8 cases (8%) out of this Mobitz type I was in 3% & Mobitz type II was in 5% cases. Incidence & mortality in relation to IInd degree heart block Type 1 & II in Group A & B was 2/0, 1/0 & 3/0, 2/1 (50%) respectively suggesting higher mortality in Type II in RV infarction than IWMI. First degree and type I second degree A-V block do not appear to affect survival, are most commonly associated with occlusion of the right coronary artery and are caused by ischemia of the A-V node. It is intermittent, transient and rarely progress to complete A-V block. Mobitz type II heart block originates from a lesion in the conduction system below the bundle of his and often progresses suddenly to complete A-V block and is almost always associated with anterior rather than inferior infarction, so it should be treated with temporary demand pacemaker. Mortality rate in present study in relation to Mobitz I & Mobitz II in IWMI was 0% & 20% & in RVI 0% & 50% respectively which indicates Mobitz II block is dangerous if ignored.

Third degree heart block (complete HB / CHB): In present study 16 cases (i.e.16%) developed this type of block in IWMI. Third degree heart block is common in inferior wall myocardial infarction because the A-V node and bundle of His is mainly supplied by the ramus septi fibrosi, a branch of right coronary artery and small twing of left coronary artery (Maurice lev). Complete A-V block can occur in patients with either anterior or inferior infarction because of dual blood supply from right and left anterior descending coronary artery. Complete A-V block develops in 5-8% of patients with AMI. The prognosis depends on the anatomical location of the block in the conduction system and size of the infarction. In general complete A-V block in patients with inferior wall infarction results from an intranodal or prenodal lesion ^[32]. The mortality is approximately 15% unless right ventricular infarction is present in which case the mortality may be doubled ^[33]. In present study total mortality rate with acute inferior wall myocardial infarction due to CHB was 7 out of 16 Patients i.e. 43.7% & and 7 out of total 25 deaths i.e. 28%. Thus incidence of mortality was higher in patients with CHB than without CHB. Incidence of mortality rate with and without heart block in various studies are as follows - Beher S. et al.^[34,35] - 27% : 11%, Clemensen P. et al. ^[36] - 20% : 4%., Kual V. et al. ^[37] - 10.7% : 5.5% respectively. Incidence & mortality in CHB in relation to Group A & B was 4/1 (25%), 12/6 (50%) respectively suggesting higher incidence & mortality in RV infarction than IWMI

Intraventricular block:-

 Bundle branch block – When conduction of the excitatory impulse is impaired or delayed through the left or right branch of the bundle of his, known as bundle branch block causing both ventricles to beat asynchronously, one contracting before the other. This result in prolongation of QRS complex. Incidence of complete bundle branch block in AMI is 10% (33). In present study total 11 cases (11%) were presented with intraventricular conduction defects with RBBB – 5% & LBBB – 3%.

Various studies showing different incidence of intraventricular blocks as shown in table no 3

Table No – 14.

The right bundle branch and left posterior division of left bundle branch have a dual blood supply from the left anterior descending and right coronary artery, whereas the left anterior, division is supplied by septal perforation originating from the left anterior descending coronary artery. In present study 8 (8%) cases were of RBBB while 3 (3%) cases were of LBBB. The incidence of RBBB is more in acute inferior wall myocardial infarction. Also incidence of RBBB is much higher than LBBB in AMI. This is because left bundle has more diffuse structure than right bundle. So that development of LBBB usually requires more extensive damage. Main left bundle branch almost invariably has double blood supply. Anterior one receives blood supply from first septal branch of anterior descending artery and posterior from A-V nodal artery. Thus presence of LBBB is only expected as a complication of large infarction involving the most of the complete heart block is frequently preceded by left bundle branch block.

In present study mortality rate in RBBB group was 6 out of 8 cases i.e. 75%, out of 25 total deaths incidence is 24% & in LBBB group was 1 out of 3 cases i.e. 33.3%, out of 25 total deaths incidence is 4%. Thus incidence of mortality in IWMI was higher in RBBB group patients. Godman et al.^[41] shown that mortality with RBBB was high i.e. 53.8% with inferior wall infarction than anterior wall 34.2% & in LBBB patients no mortality in inferior infarction but 25% in anterior wall infarction. Incidence & mortality in RBBB in relation to Group A & B was 4/3 (75%), 4/3 (75%) respectively suggesting equal incidence & mortality in both groups.

In present study titled “A study of Right ventricular involvement in acute inferior wall myocardial infarction in tertiary care center of India.” – In Acute inferior wall myocardial infarction males were more affected than female, most of the patients were from 51-60 years age group (44%) with mean age 57.4 years, most of the males (33%) were from 51-60 years group while most of the females were from 51-60 (11%) and 61-70 (11%) age group, most of the patients were (87%) admitted with complaints of chest pain.

Incidence of RVI is 46% with higher mortality of 68%. Complications and in-hospital mortality rates was higher in patients with RVI group. Incidence & mortality in Cardiogenic shock 15% & 86.6%, Bradycardia 20% & 50%, Nodal rhythm 16% & 43.7% respectively. In conduction blocks especially IIIrd degree, incidence & mortality was higher 12% & 50% respectively.

Delay in hospital admission, lack of prehospital coronary care, illiteracy, non-recognition or negligence of disease symptoms, poor transportation in rural area increases death rate.

The limitation of this study in determining risk factors, complications & conduction defects for CAD is relatively small number of patients. We suggest the conduction of larger multicenter epidemiological studies to determine statistical significance of risk factors.

1.       Jadhav UM. Cardio-metabolic disease in India-the up-coming tsunami. Ann Transl Med. 2018;6:295.

2.       GBD compare | IHME Viz Hub. https://vizhub.healthdata.org/gbdcompare/. Accessed September 17, 2022.

3.       Berger, P. and Ryan, T. (1990). Inferior myocardial infarction. High-risk subgroups. Circulation, 81(2), pp.401-411.

4.       Randomized trial of intravenous streptokinase, oral aspirin, both or neither among17,187 cases of suspected acute myocardial infarction: ISIS-2.ISIS-2(Second International Study of Infarct Survival) Collaborative Group. J. Am Coll Cardiol 1988; 12:3A-13A.

5.       Khan S, Kundi A, Sharieff S. Prevalence of right ventricular myocardial infarction in patients with acute inferior wall myocardial infarction. Int J Clin Pract.  2004;58:354e357.

6.       Erhardt C.R, Sjogren A. Wahlberg J, single right precordial lead in the right ventricular involvement in inferior wall infarction. American Heart Journal, 1976; 9: 571-576.

7.       Rechavia E, Strasberg B, Mager A, Zafrir N, Kusniec J, Sagie A, et al. The incidence of atrial arrhythmias during inferior wall myocar- dial infarction with and without right ventricular involvement. Am Heart J 1992; 124: 387-91.

8.       Bueno H, Lopez-Palop R, Bermejo J, Lopez-Sendon JL, Delcan JL. In-hospital outcome of elderly patients with acute inferior myocardial infarction and right ventricular involvement. Circulation 1997; 96: 436-41.

9.       Barrillon A, Chaignon M, Guize L, Gerbaux A : Premonitory sign of heart block in acute posterior myocardial infarction. British Heart Journal, 01 Jan 1975,37(1):2-8

10.    Yusuf S, Reddy KS, Ounpuu S, Anand S (2001). Global burden of cardiovascular diseases: Part I: General considerations, the epidemiological transition, risk factors and impact of urbanisation. Circulation .; 104:2746-2753

11.    Klein H.H. et al. - Comparison of Death Rates from Acute Myocardial Infarction in a Single Hospital in Two Different Periods (1977-1978 Versus 1988-89). The Am. J. Cardiology volume 71 march 1,1993 ; 518-23.

12.    Pulleti M. et al. - Acute myocardial infarction: sex-related differences in prognosis. Am. Heart J. 108(1) : 63 - 6 -1984.

13.    D.C.Fluk & Oslen E. et al. – Natural history and clinical significance of arrhythmias after acute cardiac infarction Br. Heart J.:– 29(2) – 170 - 189(1967)

14.    Pantridge J.F. et al.- A mobile intensive-care unit in the management of myocardial Infarction Lancet-2(7510) 271-3 (1967)

15.    Harrison’s Principles of Int. Med. – 12th Edi – 1991

16.    John G. Canto et al. - Prevalence, Clinical Characteristics, and Mortality amongPatients with myocardial infarction presenting without chest pain JAMA.2000;283(24):3223-3229.

17.    Schetdt S. et al. - Shock after acute myocardial infarction: A clinical and hemodynamic profile. Am.J. Card.- 26 : 556 (1970)

18.    Kennelly B.M.et al. - Aetiology and risk factors in young patients with recent acute myocardial infarction. S. Afr. Med. J. – 61(14): 503-7 (3 Apr. 1982).

19.    Overgaard C, Fitchett D. Cardiogenic shock from right ventricular infarction. Cardiol Rounds. 2002;VII(8).

20.    Chapra D et al. - A study of the clinical profile of right ventricular infarction in context to inferior wall myocardial infarction in a tertiary care center. Journal of Cardiovascular Disease Research 4 (2013) 170e176

21.    Erhardt LR et al. – Simple right sided precordial lead in the diagnosis of right ventricular involvement in inferior myocardial infarction. Am Heart J 1976;91:571- 576.

22.    V. Magesh et al. - A study of clinical manifestations of right ventricular myocardial Infarction. IAIM, 2018; 5(1): 121-128.

23.    Siddeswari R et al. - Clinical Profile of Right Ventricular Infarction – IJSRP - 5(4) :5-13 (2015)

24.    Varun Kumar et al. - Short-term outcome of acute inferior wall myocardial infarction with emphasis on conduction blocks: a prospective observational study in Indian population. Anatol J Cardiol 2017; 17: 229-34.

25.    Killip T. et al. – Treatment of myocardial infarction in a coronary care unit. Am. J. Cardiol. - 20: 457 - 64 (1967)

26.    Michel Oliver et al. - Problems in evaluating coronary care units Am. J. Card – 20: 465-77 (1967)

27.    Narris R.M. et al. - Bundle branch block in acute myocardial infarction - Am. – Heart. J. 79 : 728 - 33 (1970).

28.    Desmond Jullean et al. –Disturbances of rate, rhythm & conduction in acute myocardial Infarction. Am J. Med. 1964 Dec; 37:915-27

29.    Rotman M et al. – - Significance of high degree atrioventricular block in acute posterior myocardial infarction. Circulation 1973;47:257-262.

30.    Jewit D. E. et al. – Relationship between bradycardia & the site of MI Lancet – 2: 434 [1968].

31.    Gupta P.K et al. – Heart Block Complicating Acute Inferior Wall Myocardial Infarction Chest – 69 (5) : 599 (1976).

32.    Bilbao F. J. et al. – Atrioventricular block in posterior acute myocardial infarction: a clinicopathologic correlation. Circulation – 75: 733 – 6 Apr.(1987).

33.    Mavric A et al. – Prognostic significance of complete atrioventricular block in patients with acute inferior myocardial infarction with and without right ventricular involvement. - Am. Heart J. – 119: 823 (1990).

34.    Behar S. et al. – Complete atrioventricular block complicating inferior acute wall myocardial infarction: Short- and long-term prognosis.- Am. Heart J - 125 (6):1622-7(June 1993).

35.    Behar S. et al. – Circadian variation and possible external triggers of onset of myocardial Infarction - Am. Heart J. -m 94 (4): 395 – 400 (Apr. 1993).

36.    Clemmensen P. et al. – Complete atrioventricular block complicating inferior wall Acute myocardial infarction treated with reperfusion therapy - Am. J. Cardiol 67 (4) : 225 – 30 (Feb. 1991).

37.    Kaul V, Haron H. et al. – Significance of advanced atrioventricular block in acute myocardial infarction – A study based on ventricular function & holter monitoring. Int J cardiol – 11 (2) : 187 – 93 [may 1986].

38.    Atkins J. et al. – Prognosis of right bundle branch block and left anterior hemiblock: A new indication for permanent pacing Am. J. Cardiol – 26 : 624 (1973).

39.    Carlos A.E. Basualdo. et al. – Intraventricular Blocks in Acute Myocardial Infarction Chest – 67 : 75 (1975).

40.    Jones M. E. et al. – Frequency and significance of conduction defects in acute myocardial infarction. Am. Heart J. – 94 : 163 (1977).

41.    Godman m. J. et al. – Complete Bundle-Branch Block Complicating Acute Myocardial Infarction - NEJM – 282 : 237 (1970).