Rajiv Ghandhi University of Health Sciences,Karnataka

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES,

BANGALORE,KARNATAKA.

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

6.BRIEF RESUME OF THE INTENDED WORK

6.1NEED FOR THE STUDY:

Sudden death is defined as either an unexpected natural death within one hour or less from the onset of symptoms;or non witnessed death discovered within 24hours in someone without prior symptoms or any prior condition that would appear fatal.The overwhelming majority of natural deaths are caused by cardiac disorders.1The commonest cause of sudden cardiac death is ischemic heart disease and non ischemic sudden cardiac death occurs in hypertrophic cardiomyopathy, congenital coronary anomalies, coronary emboli, mitral valve prolapse and myocarditis.2

The conventional method of heart dissection is inflow outflow method. This method will not expose completely the left ventricular wall, right ventricular wall and the interventricular septum. Thus fails to demonstrate satisfactory clinicopathological correlation in cases of sudden cardiac death. The reason being the isolated interventricular septal thickening in cases of cardiomyopathies, myocardial infarction due to obstruction of right coronaries and sudden death due to acute myocardial infarction. To overcome above deficiencies we are using short axis method. By doing short axis method we will be exposing entire circumference and the thickness of left ventricle, right ventricle and interventricular septum. This is the best technique for inspecting the myocardium for infarcts. 3,4,5

Triphenyl tetrazolium chloride helps us to pick up ischemic change as early as 2-6hrs. Masson trichrome stain helps us to demonstrate the interstitial fibrosis. Morphometry of myocardial fibre will aid in assessing the hypertrophy of individual fibres. This is an attempt to utilize the above parameters to increase satisfactory clinicopathological correlation in sudden death.

6.2REVIEW OF LITERATURE:

The vast majority of naturally occurring sudden deaths are caused bycardiac disorders.As per WHO census statistics, mortality due to cardiac cause has overtaken mortality due to all cancer put together. 4280 out of every 1 lakh people die every year from sudden cardiac death in India alone. Sudden cardiac death accounts for 3,00,000 to 4,00,000 death annually in US.6

80% of sudden cardiac deaths in individuals >35yrs is due to ischemic heart disease, followed by hypertrophic cardiomyopathy(5%), valvular heart disease(5%), mitral valve prolapse(5%), unexplained(5%). Whereas in individuals <35years of age hypertrophic cardiomyopathy accounts for 48% of sudden cardiac death.7

Cardiomyopathies represent second largest group of patients who experience sudde

n cardiac death.8 .The incidence of hypertrophic cardiomyopathy in United staes is low and accounts0.02 to 0.2 percent of the population and is found to be in0.5% of un-selected patients referred for an echocardiographicexamination.9 In Japan the prevalence per 100,000population is 17.3 which is same as in the Western population.10The condition is being increasingly recognised in India and yet, there is little data available regarding the incidence and the rates of mortality.11

In a study at University of Leuven, myocardial infarct size was determined in 54 slices by the TTC technique and histologically. The findings were similar with close correlation between the two methods.12

In another study, the overall efficacy of TTC test in 638 cases of acute myocardial infarction leading to sudden death was found to be 88%.13

Very few studies are available to evaluate the diagnostic utility of short axis method. So, this is one study which will help us in better evaluation of cardiac disease in sudden death.

6.3 OBJECTIVES OF THE STUDY:

1.To assess the diagnostic utility of short axis method over inflow outflow method of heart dissection.

2. To assess the necessity of triphenyltetrazolium chloride staining to pick up acute MI of 2-6hrs.

3. To evaluate role of morphometry and special stains in assessing the incidence of hypertrophies.

7. MATERIALS AND METHODS:

7.1 SOURCE OF DATA:

All cases of sudden deaths with eitherhistory, risk factor or gross features of heart suggestive of death due to cardiac origin. Such cases will be subjected for medicolegal autopsy at the Department of Forensic Medicine. Histopathology examination will be done in Department of Pathology, Victoria hospital, Bangalore.

7.2 MATERIALS ANDMETHODS:

A) STUDY DESIGN:

Prospective study

B)STUDY PERIOD:

Oct 2013 to May 2015

C)PLACE OF STUDY:

Department of Pathology, Victoria Hospital, Bangalore.

D) SAMPLE SIZE:

Minimum of 60, but all the cases during study period will be included.

E) INCLUSION CRITERIA:

1. All cases of sudden death occurring in the study period, mainly fresh hearts and those with proper storage.

F)EXCLUSION CRITERIA:

1. Cases in which autopsy is not possible.

2. Cases without proper cold storage.

G)METHODOLOGY:

The study will be carried out at the Department of pathology and department forensic Medicine during the period of October 2013 to May 2015. Minimum of 60 cases will be studied. The heart will be dissected out, washed and weighed followed by gross examination for any pathology. 30 hearts will be opened by inflow outflow method. In this technique, for each side of the heart, the atrium is opened first, and then theventricle is opened alongits inflow and outflow tracts,following the direction of blood flow.And 30 heartswill be opened by short axis method.In this method, transverse slices of the heart 1.0-1.5cm thick parallel to atrio-ventricular groove starting from apex was made using long knife. Remaining hearts inflow outflow and short axis method will be used alternately. Morphometry of myocardial fibres will be done using Olympus BX51 microscope. Histochemical staining will be done by triphenyltetrazoliumchloride and special staining by masson trichrome using standard methods.

H) STATISTICAL ANALYSIS:

Descriptive analysis will be used(means, proportions,percentage) for demographic details. Difference between continuous variables among groups will be assessed by student t test. Categorical variables will be compared using chi square test and Fischer’s exact test. P value of <0.05 is considered significant.

7.3DOES THE STUDY REQUIREANY INVESTIGATION OR INTERVENTION TO BE CONDUCTED ON HUMANS OR ANIMALS?

Yes.Human cadaver is subjected to post mortem examination and heart is studied in detail.

7.4 HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION.

Obtained.

8. LIST OF REFRENCES:

1. Longo, Fauci, Kasper, Hauser, Jameson, Loscolzo ,Harrison’s principle of internal medicine,18th e, volume 2, pg 2238-2246.

1. M. Ahmad, S. Afzal, I. A. Malik, S. Mushtaq, A. Mubariket al,An Autopsy Study of Hypertrophic Cardiomyopathy,journal of Pakistan medical association, Vol 53, No.10,Oct 2003.

3. Banshidhar Gupta, Hetal Gohel, Dr. Nandini Desai,Shital Dodhia et al,post mortem study of heart in cases of sudden cardiac death using triphenyltetrazolium chloride and haemtoxylin and eosin stain, I.J.A.B.M.S., july 2013, 112-114.

4. Finkbeiner, Ursell, Davis,Autopsy Pathology: A Manual and Atlas, 2nd edition, p42.

5. Jurgen Ludwig's Handbook of Autopsy Practice.

3rd edn.p21-35.

6. Engelstein ED,Ziper DP, SCD,In;Alexander RW,SchlantRC,Fuster V,The heart, arteries and veins,New York;McGraw hill, 1998,1081-1112

7. Maron bj,Epstein SE, Roberts WC; causes of sudden death in competitive athletes, journal of American college of cardiology, 1989;204-214.

8. SpiritoP,SEidman CE, McKEnna WJ, Management of HCM, N Engl J of medicine, 1997.

9. Maron BJ, Peterson EE, Maron MS, et al. Prevalence of hypertrophic cardiomyopathy inan outpatient population referred for echocardiogrpahic study. Am J Cardiol,1994;73:577-80.

10. Miura K, Nakagawa H, Marikawa Y, et al. Epidemiology of idiopathic cardiomyopathy in Japan: results from a nationwide survey. Heart 2002;87:126-30.

11. RS Phadke, P Vaideeswar, B Mittal, J Deshpande et al,Hypertrophic cardiomyopathy: an autopsy analysis of 14 cases, journal of postgraduate medicine,vol 47,issue 3,2001, pg:165-170.

12. Fishenbein MC, Meerbaum S,Ritz J, Lando RH, Kanmatsuse K, Mercier JC, Corday E, Ganz W. Early phase acute myocardial infarct size quantification; validation of Triphenyl Tetrazolium chloride tissue enzyme staining technique. Am Heart J.1981 May; 101(5):593-600.

13.Ramesh KK, Bhullar DS, Mohanvir K. The Autopsy Diagnosis of early myocardial infarction(MI)by Triphenyl Tetrazolium Chloride (TTC) or nitroblue tetrazolium (NBT) dye test. J Punjab Acad Forensic Med Toxicol 2012; 12(1):60.

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