Conduction Disturbances in Hypertension

Suresh Prabu, B (2006) Conduction Disturbances in Hypertension. Masters thesis, Stanley Medical College, Chennai.


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INTRODUCTION: Hypertension is one of the most common diseases of mankind which results in a very high incidence of morbidity and mortality. Hypertension is the most important public problem of the modern world. It is one of the most common diseases which are easily detectable, effectively treatable and leading to fatal complication if left untreated. The understanding of the pathophysiology of the hypertension has widened, still about 90 to 95% of the causes do not have an identifiable cause and is known as primary or essential hypertension. In small group of hypertension 5 to 10% an etiology could be identified, this is the secondary hypertension. According to JNC 7, hypertension is said to be present when the systolic and diastolic blood pressure exceeds 140 and 90 mm Hg respectively. Hypertension causes an increase in left ventricular mass resulting in increased stiffness of the left ventricle leads to reduced coronary reserve silent myocardial ischemia, and abnormal electrophysiological property of hypertrophied myocyte and conduction disturbances. These changes probably accounts for the increased morbidity and mortality associated with hypertensive heart disease. Hypertension is also associated with increased cerebrovascular accidents. In the assessment of cardiac status in such patients ECG forms an important investigatory procedure and a very economical tool and easily applies to large number of population. Though normal ECG may be found in many cases of moderate to severe hypertension it still remains a useful means of diagnosis of hypertension associated with axis deviation, bundle branch block, fascicular block and myocardial infarction associated with hypertension. AIMS: 1. To study the incidence of conduction disturbances in patients with primary hypertension, 2. To identify the most common type of conduction defect and incidence among males and females. 3. The identify the role of diastolic blood pressure that will affect the prevalence of conduction disturbances. MATERIALS AND METHODS: Study Place: This study was conducted at HYPERTENSION CLINIC of MEDICINE DEPARTMENT in every Monday and Saturday in Government Stanley Hospital during August 2004 to April 2005. Study Population: This study is based on the analysis of the ECG of 800 patients who attended the hypertension clinic. It included 545 male patients and 255 female patients. Inclution Criteria: 1. Patient who had established hypertension and who were in regular antihypertensive medication. 2. Only those patients with proved Primary hypertension were included in this study. 3. Of these, patients with consistent elevation of blood pressure over a period of three weeks only were taken up for ECG analysis. Exclution Criteria: 1. The patients with secondary hypertension and diabetes mellitus are excluded. 2. The patients with Isolated Systolic Hypertension are excluded. 3. The patients with Non Sustained hypertension are excluded. METHOD: Blood pressure was measured in all the four limbs, recumbent, sitting and standing postures were used. • Routine urine analysis and blood for Urea, chlostereral, Electrolyte and Creatinine were done. • Complete clinical examination was done to exclude the possibility of secondary hypertension. • Standered 12 leads ECG was taken and the patient who were having ECG abnormality were followed up a week later with another ECG and only patients with persistent abnormality were taken for analysis. OBSERVATION: The ECG of 800 consecutive patients with persistent hypertension was analyzed for Conduction defect as described above. 94 cases have abnormal ECG’s of which Left ventricular hypertrophy with and without strain formed the main abnormality in this study. Conduction disturbance in the form of RBBB, LBBB, LAFB were present in 10% of cases. Among which LAFB was the most common type of Conduction disturbance and it constitute7.25%. Thirteen ECG’s with LAFB also showed features of LVH with strain. Ten ECG’S showed LAFB had feature of Anterolateral myocardial Ischemia as well as one ECG with LAFB had LVH without strain. Two EEG with LAFB showed evidence of old ASMI. Two ECG with LAFB showed LVH with evidence of diastolic overload, Eight ECG showed Ventricular premature Contracture. Among the EEG with evidence of RBBB, six of them had Ventricular hypertrophy. Ten ECG showing LBBB was not associated with any evidence of ischemia, Ventricular hypertrophy. NO case with LPFB was observed among the abnormal electrocardiogram. SUMMARY: This study was conducted among 800 patients with hypertension attending Hypertension clinic at GOVERNMENT STANLEY HOSPITAL – CHENNAI from August 2004 to April 2005. Standard 12 leads ECG was recorded in all patients and analyzed for the presence of intraventricular conduction defect like RBBB, LBBB, LAFB and LPFB ect. using the standard electrocardiographic criteria for such defects. Our analysis of the ECGs showed the presence of abnormal ECGs in 37.75% of patients. Commonest abnormality is LVH (11.75%) followed by Conduction disturbance (10%), myocardial ischemia (9.5%), old Myocardial infarct (3%), Left axis deviation (2.5%), Ventricular premature contraction (1%). while 62.25% of patients had a normal ECG. The result of our studies proves that hypertension is frequently associated with the development of conduction disturbances and increased severity of hypertension may be related to increased incidence of such defect. The identification of which may be helpful in defining high risk groups and start appropriate therapy to prevent complications and to reduce the morbidity and mortality. CONCLUSION: 1. This study proves that intraventricular conduction disturbance is one of the commonest electrocardiographic manifestations in Primary hypertention. 2. Left anterior fascicular block (7.25%) is the commonest one followed by Right (1.75%) and Left bundle branch block (1%). 3. With increasing diastolic BP conduction disturbances become more common.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Hypertension ; Conduction Disturbances.
Subjects: MEDICAL > General Medicine
Depositing User: Subramani R
Date Deposited: 23 Mar 2018 03:57
Last Modified: 24 Mar 2018 04:32

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