Download RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES KARNATAKA,

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES KARNATAKA,
BANGALORE
ANNEXURE 2
PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION
1.
Name of the candidate and address (in
block letters)
DR.SANJEEV.V.CHINTAMANI
TAJ RESIDENCY,ROOM NO -105
DERALKATTE MANGALORE
2.
Name of the institute
YENEPOYA MEDICAL COLLEGE, MANGALORE
3.
Course of study and subject
MD. GENERAL MEDICINE
4.
Date of admission to course
23rd APRIL 2008
5.
Title of the topic
A PROSPECTIVE COHORT STUDY OF THE TEMPORAL PROFILE
OF QT DISPERSION IN ACUTE MYOCARDIAL INFARCTION
6.
Brief resume of the intended work
6.1 Need for study

Within the acute complications of Acute Myocardial Infarction, ventricular arrhythmias are a
very important yet preventable cause of death (1).

The absolute number of patients who will have MI is expected to increase in the future.
Accordingly, sudden cardiac death after MI will continue to be a significant clinical problem.
Identification of MI patients with preserved LVEF >40% at risk of dying suddenly, however, is an
unresolved clinical challenge (2).

Sophisticated tests like Microvolt T wave alternans, domain ventricular late potentials, non
sustained ventricular tachycardia on Holter monitoring have been well studied, but are
unavailable to most people (3).

There is a need to define reliable and affordable parameters to measure or stratify the risk of
ventricular arrhythmia in the setting of acute myocardial infarction .

QT variation and QT dispersion may provide a potentially simple, cheap and non invasive
method of measuring underlying dispersion of ventricular excitability (5),(6).
6.2 Review of literature

Parale and co-workers from Sholapur (Maharashtra) studied dynamics of QT dispersion in
patients with Acute MI and compared it with those in controls. With serial measurements of QT
interval and QT dispersion, they found that the mean QT dispersion was significantly higher in
patients with Acute MI as compared to controls. QT dispersion showed a dynamic change in
patients who where thrombolyzed. There was marked decrease in QT dispersion in those
patients who were thrombolyzed as compared to those who were not. It was also noted that
mean QT dispersion values were higher in patients with ventricular arrhythmias compared to
patients with Acute MI without arrhythmias (6).

Study was conducted in Aurangabad to find out QT dispersion in healthy individuals and
patients of Acute MI and to find correlation, if any, between QT dispersion and incidence of
ventricular arrhythmias in Acute MI patients admitted in ICU. They calculated QT dispersion at
admission, 24hrs after admission and at discharge from ICU. Average QT dispersion in Acute MI
was found to be significantly higher on admission, 24hours after admission and at time of
discharge from ICU than in healthy individuals. QT dispersion was found to be significantly
increased in patients of Acute MI with ventricular arrhythmia than in those without. It was also
found that QT dispersion was significantly greater in patients with Anterior wall MI than in
those with Inferior wall MI (7).

A group of doctors from Department of Angiology in Ankara, Turkey conducted a prospective
study to know the ideal time to measure QTD for risk stratification after AMI. Sequential
changes of corrected QTD were studied in 136 patients from day1 to day 30 after AMI in
patients treated with thrombolytics. 65 healthy individuals were taken as controls. 14 patients
in whom arrythmia or sudden cardiac death occurred over 30 days were also noted. ECG was
done at day 1, 3, 5, 10, 15 and 30. It was noted that QTc was more prolonged in AMI patients
than in controls. QTc was greater in patients treated without thrombolytics than those treated
with thrombolytics for every period (1, 3, 5, 10, 15 & 30). Mean of QTcD was significantly
greater in patients who developed arrythmia than those who did not. Maximum QTcD was
seen on day 10 after MI and then reached a plateau for each group. The ideal time to measure
the QTD for risk stratification is at least 10 days after AMI (8).

A prospective cohort study was done by Academic Department of Cardiology, Freeman
Hospital, Newcastle, UK. 201 patients who had AMI were studied over a period of eight
months. 12 patients developed ventricular fibrillations within 24hrs. Neither QTd nor QTcd
differed between those developing ventricular fibrillation and those who did not. Significant
QTcd changes occurred early after AMI. It was concluded that QTd or QTcd do not predict
ventricular fibrillation after AMI (9).
6.3 Objectives and Aims of the study

To study the temporal profile of QT dispersion recorded by surface electrocardiography in
patients admitted with Acute Myocardial Infarction, and comparing them with controls.

To study the effects of thrombolysis on QT dispersion in patients admitted with Acute
Myocardial Infarction.

To study the correlation of QT dispersion with the incidence of in-hospital ventricular
arrhythmias
Materials and Methods
7.1 Inclusion criteria
Source of data

7.
Hospital admitted patients above 18 yrs diagnosed as Acute MI on the basis of clinical
presentation, electrocardiographic criteria and elevated cardiac enzymes (CKMB).
7.2 Exclusion criteria

Medical conditions that could affect QT interval, such as Electrolyte imbalance, Left & Right
Bundle Branch Block, Atrial fibrillation

Patients taking drugs that affect QT interval: amiodarone, cisapride, macrolide antibiotics, etc.
7.3 Method of collection of data (including sampling procedure if any)
SAMPLE SIZE :
50 patients of Acute MI.
50 patients age and sex matched Controls

Study wil be conducted from November1 2008 to October31 2009.

Detailed history and clinical examination of selected patients will be done

CK-MB and serial ECG recordings on admission, day 2 & at day 5 will be done

QT interval will be measured in all leads from onset of QRS to end of T wave. If U wave is
present, QT interval will be measured till nadir of curve between T and U waves.

Corrected QTc will be calculated as QT interval/square root of previous R-R interval using
Bazett’s formula.

QTd(qt dispersion) will be calculated as:
QTd= (max QT interval-min QT interval).

Cases will be divided into
A) Study group (MI patients) and Control group (age and sex matched normals)
B) Thrombolysed and not Thrombolysed group (8).
C) Ventricular Arrhythmia and No Ventricular Arrhythmia group (6).
The data obtained will be tabulated as
n
Admission
Day 2
Day 5
Control
Acute MI
STK given
STK not given
Ventricular
Arrhythmia
No Ventricular
Arrhythmia
Where MI= Myocardial infarction; n= no of cases
7.4 STATISTICAL ANALYSIS
Tests of significance (Student’s T test and p value) will be applied to the data to observe statistical
significance .
7.5 Does the study require any investigations or interventions to be conducted on patients or other
humans or animals? If so please describe briefly.
After history taking and systemic examination the subjects will be assessed for cardiac enzymes by
blood examination and electrocardiography will be done. This will be done only after counseling the
patient to the best of my ability and obtaining consent from the patient. Irrelevant investigations or
invasive interventions causing any pain or discomfort to any patient solely for the purpose of this
dissertation will not be done.
7.6 Has ethical clearance been obtained from your institution in case of 7.5?
Yes
8.
List of references
1. Haghjoo M, Kiani R, Fazelifar AF et al. Early risk stratification for arrhythmic death in patients with
ST-Elevation Myocardial Infarction. Indian Pacing Electrophysiol J. 2007 Jan–Mar; 7(1): 19–25.
2. Klingenheben T. Arrhythmia risk prediction in patients with preserved left ventricular ejection
fraction; Final frontier? J Am Coll Cardiol. 2006; 48(11): 2275-2276.
3. Sahu P, Lim PO, Rana BS, Struthers AD.QT dispersion in medicine. Q J Med. 2000; 93: 425-431.
4. McComb CP, Campbell RW. QT dispersion-an indication of arrhythmia risk in patients with long QT
intervals. Br Heart J. 1990; 63: 342-344.
5. Pye M, Quinn AC, Cobbe SM. QT interval dispersion: a non-invasive marker of
susceptibility to arrhythmia in patients with sustained ventricular arrhythmias? Br Heart J. 1994; 71:
511–514.
6. Parale GP, Adnaik AR, Kulkarni PM. Dynamics of QT dispersion in patients in Acute Myocardial
Infarction. Indian Heart J. 2003; 55(6): 628-31.
7. Mulay DV, Quadri SM. QT dispersion and early arrhythmic risk in acute Myocardial Infarction. Indian
Heart J. 2004; 56: 636-641.
8. Kabakci G , Onalan O , Batur MK , et al. What is the Optimal Evaluation Time of the QT Dispersion
After Acute Myocardial Infarction for the Risk Stratification. Angiology. 2001; 52(7): 463-468.
9. Aitchison JD, Campbell RWF, Higham PD. Time dependent variability of QT dispersion after acute
myocardial infarction and its relation to ventricular fibrillation. Heart. 2000; 84: 504–508.
9.
Signature of candidate:
10.
Remarks of the Guide
11.
Name and Designation of
11.1 Guide
Dr.Ravi. Vaswani
Professor in Department of Medicine
Signature
Yenepoya Medical college, Mangalore
11.2 Co Guide(if any)
Signature
11.3 Head of the DEP
Dr. Mohammad. Kunhi
HOD and Professor in Department of Medicine
Signature
12.
Principal
12.1 Remarks of the Principal
Yenepoya Medical College, Mangalore