Prevalence of Left Ventricular Hypertrophy in Patients with Essential High Blood Pressure
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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
l To study the prevalence of left ventricular hypertrophy in patients with essential HBP.
l To analyze the diagnostic efficacy of EKG and ECHO in determining LVH variants.
l To determine left ventricular geometric alterations in relation to age, sex, skin color, body mass index (BMI),
classification and duration of HBP, and risk factors.
MATERIAL AND METHODSA 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/m 2 (females), and for RWT
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.
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2nd Virtual Congress of Cardiology
Dr. Florencio Garófalo Dr. Raúl Bretal Dr. Armando Pacher
Steering Committee Scientific Committee Technical Committee - CETIFAC
President President President
fgaro@fac.org.ar rbretal@fac.org.ar apacher@fac.org.ar
fgaro@satlink.com rbretal@netverk.com.ar apacher@satlink.com
Copyright© 1999-2001 Argentine Federation of Cardiology
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