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Prevalence of Left Ventricular Hypertrophy
in Patients with Essential High Blood Pressure

Delgado Vega, Mirtha; Medina Fernández, Angel;
Agüero Batista, Nilvia; Delgado Flores, Mayte;
Delgado Flores, Enrique; Menéndez Cabezas, Arturo

Medical University "Carlos J. Finlay", Camagüey, Cuba

SUMMARY
Because of its frequency, consequences and complexity, high blood pressure (HBP) has become the main clinical problem in adults, in a society with a growing specific weight of the advanced age population. Despite the increasing public awareness, HBP remains one of the commonest risk factors of cardiovascular morbidity and mortality.
In this research, the prevalence of left ventricular hypertrophy (LVH) in patients with essential hypertension was studied, considering different geometric alterations of the left ventricle in relation to several variables such as age, sex, race, body mass index (BMI), classification and duration of HBP, as well as different risk factors. In addition, a comparative analysis of the diagnostic efficacy of the electrocardiography and echocardiography was carried out.
It was a descriptive cross-sectional study with a sample of 200 patients with essential hypertension of 18 years and older and of both sexes. For each patient all the mentioned variables were recorded and an electrocardiogram and an echocardiogram were performed. The electrocardiogram was the standard type and the indexes of Sokolow and Cornell served as the criteria for the LVH.
The echocardiography studies were the best diagnostic tool for measuring left ventricular variations of the geometric pattern. Results showed an overall of 135 hypertensive patients with altered ventricular geometric pattern, of the three variants and in particular that of the concentric hypertrophy, in the age group 60 - 73 years-old, in males, in patients with severe HBP and a duration of more than one year, in obese patients and in those suffering Diabetes Mellitus.

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INTRODUCTION
   High blood pressure (HBP) continues to be one of the commonest risk factors of cardiovascular morbidity and mortality (1,2). From its very beginning it is a heart disease and if not controlled may lead to heart failure, being its main cause in the most developed countries (3). Its high mortality is related to left ventricular hypertrophy (LVH). It has been shown that the increase in the left ventricular mass (LVM) is the independent risk variable of the highest value in cardiovascular morbidity (4,5,6). This relates to many factors, hemodynamic, individual and trophic, which adversely act upon heart contractility, perfusion and electric activity. LVH occurrence leads to a four-fold increase in the incidence of lethal ventricular arrhythmias, ischaemic cardiopathy and acute myocardial infarction, constitutes an increased probability of sudden death and multiplies by 10 the frequency of congestive heart failure (7,8).

   Electrocardiographic signs of LVH are seen very late in the disease history and reflect a very advanced stage of it. Echocardiography (ECHO) has a superior sensitivity, together with good specificity, and allows to determine the diverse LVH forms (8). Therefore, it appears to be a more effective diagnostic method (9 - 13). This study allows to determine the significance of this method in our environment, to group HBP patients in those who have developed LVH or not (9, 10), shall provide scientific knowledge about this pathology, and the results will help in developing a more effective rehabilitation leading patients to resume with better quality and earlier to work and social life.

OBJECTIVES

MATERIAL AND METHODS
   A descriptive study was carried out. From a universe of 4140 patients with essential HBP of a primary health care area (Polyclinic Finlay, Camagüey City), a random sample of 200 patients of both sexes and over 18 years of age was taken. For each patient were recorded age, sex, skin color, body weight and height. BMI was calculated and patients classified in obese (BMI > 30), overweight (BMI = 25.0 to 29.9), normal weight (BMI = 20.0 to 24.9), and low weight (BMI < 19.9). Patients were also classified according to the time of HBP evolution and its type (severity). Standard EKGs were performed using a monochannel electrocardiograph Nihon Kohden BA-601 D at 25 mm/s. It was interpreted according to the Minnesota Code (14). Criteria for LVH were the Sokolow and Cornell indexes (15). ECHOs were carried out with a multipurpose echocardiograph Shimadzu SOU-700 and a sectorial electronic transductor of 3.75 MHz using the modes M and bidimensional at a speed of 500 mm/s with the patient lying on its back after 10 minutes resting (11). Diastolic measurements in different cardiac cycles were obtained, the interventricular septum, the left ventricle posterior wall and the left ventricle diameter, used for the calculation of the left ventricular mass, the left ventricular mass index (LVMI), and the relative wall thickness (RWT) (9, 11). The normal values for LVMI were considered < 112 g/m2 (males) and < 107 g/m2 (females), and for RWT <0.44 (both sexes). The LV geometric pattern was estimated according to the following scheme (12): (Table 1).

Table 1

   Results were processed using the statistics program Microstat.

RESULTS
   The sample consisted of 93 women and 107 men. The EKG did not allow to detect any case of LVH using the Sokolow Index, and only 7 cases could be diagnosed using the Cornell criteria. On the other hand, ECHO made possible to classify patients according to the LV geometric pattern in: 65 N (32.5 %), 68 CR (34.= %), 27 EH (13.5 %) and 40 CH (20.0 %), for a total of 135 patients with LV geometric changes, of which 67 (33.5 %) had a frank LVH.

   By age groups, a significant low percentage of LV normal pattern was observed in the groups 60-73 and 74 & more. It is remarkable that 62.5 % of the members of the group 74 & more had CH (Fig. # 1).

   Regarding sex, the lowest percentage of patients with normal pattern corresponds to men, in which CR was predominant, however, in comparison with women, men had a higher percentage of EH (Fig. # 2).

   Figure # 3 shows a higher percentage of black patients with abnormal geometric patterns in comparison with white patients, more significant with regard to EH and CH.

   Regarding the nutritional status determined by BMI, figure # 4 shows that the highest percentage of cases with abnormal geometry corresponds to patients classified obese, nevertheless it is remarkable the clear predominance of CH in the group of low weight, and the relatively high percentage of patients classified as normal with EH in comparison with the other groups.

   Figure # 5 shows that the lowest percentage of patients with normal geometric pattern corresponded to those with HBP lasting more than 20 years. The highest percentages for CR were observed in the groups 1 - 5 years and > 20 years, while for CH in the groups < 1 year, 1 - 5 years, and > 20 years.

   There were significantly more patients with severe HBP who had LV anatomic alterations, prevailing EH, while the highest percentage of patients with CH corresponded to those with moderate hypertension (Fig. # 6).

   Figure # 7 shows the LV geometric patterns of these patients in relation to various risk factors. Patients with Diabetes Mellitus had the lowest percentage with normal geometry, and together with those suffering alcoholism were the most affected with CH.

DISCUSSION
   The primary objective of HBP treatment is to reduce the risk of cardiovascular morbidity-mortality, from which arises the importance of in time detection of LV geometric alterations in order to undertake the corresponding therapeutic measures (16). Our study endorses the advantage of ECHO vs. EKG for determining the variants of heart anatomical alterations (17). 67.5 % of patients under study had any of the geometric alterations forms, almost half of them had a typical LVH, and although this was more significant in advanced ages, in young patients the 3 variants were present. With age the hypertrophic response against the volume or pressure overload increases (16). Men showed more anatomical alterations of myocardium than women. This can be due to endocrine and metabolic characteristics and the association of risk factors common in men (15). In the sample white patients were the majority, a peculiarity of this province, but although the number of black patients is very low the results show a trend in them toward heart damage (18, 13). Obesity determined by BMI was confirmed as a negative factor of the LV anatomy, but the results obtained in the low weight group represent a warning and raise a scientific challenge: to deeply study the long-term effects of perinatal nutrition (20). The duration and severity of HBP obviously have a repercussion upon the LV geometry (16), and it is alarming that a substantial number of patients with moderate HBP showed CH, which has the worst prognosis (16), however, one cannot disregard the association of some of the other studied factors. The importance of pathological antecedents and of recognized risk factors was underlined by our results, leaving no doubts that in hypertensive patients the factor with the worst prognosis is Diabetes Mellitus (21, 16, 19).

CONCLUSIONS

1- Echocardiography was the most significant diagnostic criterion for measuring left ventricular geometric pattern variations in essential HBP patients.
2- The prevalence of LVH is relatively high in adult patients with essential HBP.
3- The left ventricular geometric alterations in essential HBP patients are more frequent and severe in advanced ages, in males, in those with severe HBP and evolution of more than a year, in obese patients and in those suffering Diabetes Mellitus.

REFERENCES

1. J.L. Palma, E. Alegría Ezquerra, F. De Lombera Romero. Hipertensión y cardiopatía hipertensiva. Sociedad española de Cardiología. Madrid. España 1996: 3.

2. Gordon N. Gill, Thomas Woodward Smith, Fred Plum. Hipertenão arterial. Cecil: Tratado de Medicina Interna. 6ª Edição. 1996: 285-300.

3. World Health Organization Expert Committee on Arterial Hypertension. Geneva: World Health Organization. 1978 (WHO). Technical report series, N° 628.

4. Casale P.N., Devereux R..B, Milner M, et al. Value of Echocardiographic measurement of left ventricular mass in predicting cardiovascular morbid events in hypertensive. Men. Ann. Intern. Med. 1986; 105: 173-178.

5. Levy D, Garrison R.J., Savage D.D., Kannel W.B., Castelli W.P. Prognostic implication of echocardiographically determined left ventricular mass in the Framingham Heart Study. N. Engl. J. Med. 1990; 322:1561-66.

6. Kannel W.B., Dannenberg A.L., Levy D. Population implication of electrocardiographic left ventricular hypertrophy. Am. J. Cardiol. 1987;60: 851-931.

7. Diez J., Coca A., Teresa E., Labiades C., López-Sendón J.L., Tamargo J. Remodelado y reparación cardiovascular. Diez J. Madrid; Ed. Ergon 1995.

8. McLenachan JM, Dargie HJ. Ventricular arrhythmias in hypertensive left ventricular hypertrophy. Relationship to coronary artery disease, left ventricular dysfunction and myocardial fibrosis. Am J Hypertension 1990; 3 (10):735-40.

9. Devereux R, Reichek N. Echocardiographic determination of left ventricular mass in man. Circulation 1977; 55: 613-618.

10. Sahn DJ, De María A, Kisslo J, Weyman A. The committee on M mode standardization of the American Society of Echocardiography: recommendations regarding quantification in M mode echocardiography: results of survey of echocardiography measurements. Circulation 1978; 58: 1072-1083.

11. Asin Cardial E., Mortera C., Yuste P. Ecocardiografía. Nuevas técnicas. Ciudad de La Habana: Científico Técnica, 1979: 25-27.

12. Ganan A. Patterns of left ventricular hypertrophy and geometric remodeling in essential hypertension. J. Am. Coll. Cardiol. Jun 1992; 19(7): 1550-58.

13. Hammond I.W., Alderman M.H., Devereux R.B., Lutas E.M., Laragh J.H. Contrast in cardiac anatomy and function between black and white patients with hypertension. J. Natl. Med. Assoc 1984; 76: 247-55.

14. Rose G., Blackburn H. Cardiovascular survey methods. WHO 1968; 56: 137.

15. Casale P.N., Devereux R.B., Alonso D.R., Campo E., Kligfield P. Improved sex-specific criteria of left ventricular hypertrophy for clinical and computer electrocardiogram interpretation: validation with autopsy findings. Circulation 1987; 75: 565-572.

16. Rodríguez Padial L., Sánchez Domínguez J. Patogenia y Fisiopatología de la Hipertensión Arterial y de la Cardiopatía Hipertensiva, 1996; 3: 22-23. En: Ed.: Palma Gámiz J.L., alegría Ezquerra E., De Lombera Romero F. Hipertensión y Cardiopatía Hipertensiva. Actualización y recomendaciones del Grupo de Trabajo de Hipertensión Arterial, Sociedad Española de Cardiología. Madrid. Editora Mosby-Doyma Libros S.A.

17. Kaplan NM. Systemic hypertension: mechanisms and diagnosis. In: Braunwald H. Ed. Heart Disease. A Textbook of cardiovascular medicine. Philadelphia, WB Saunders, 1992: 817-851.

18. Dunn FG, Oigman W, Sungaard-Riise K, et al. Racial differences in cardiac adaptation to essential hypertension determined by Echocardiographic indexes. J Am Coll Cardiol 1983; 1: 1348 -1351.

19. Frohlich E.D. Left ventricular hypertrophy as a risk factor. In: Messerli F.H., Amodeo C, eds. Cardiology clinics, vol. 4 Philadelphia, WB Saunders 1986; 137-144.

20. Waterland R.A., Garza C. Potential mechanisms of metabolic imprinting that lead to chronic disease. Am J Clin Nutr 1999; 69: 179 - 197.

21. Weber JR. Left ventricular hypertrophy: Its prime importance as a controllable risk factor. Am. Heart J. 1988; 116: 272-279.

 

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2nd Virtual Congress of Cardiology

Dr. Florencio Garófalo
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