EVALUATION OF PEGUERO-LO PRESTI CRITERIA FOR ASSESSMENT OF LEFT VENTRICULAR HYPERTROPHY.

Background and objectives: The sensitivity of ECG to diagnose LVH by Peguero-Lo Presti criteria has shown higher sensitivity when compared to well established criterion like Cornell voltage and Sokolow Lyon criteria. This study was aimed to find the accuracy of Peguero Lo Presti criteria in the diagnosis of LVH in patients with hypertension. Methodology: This one cross-sectional study was conducted in the Department of Cardiology of a tertiary care centre in North Karnataka from May 2017 to October 2017. A total of 400 patients with age > 30 years having hypertension were studied. All the patients were subjected to ECG and 2D echo. Results: In this study majority (73.5%) of the patients were males and male to female ratio was 2.77:1. Most of the patients were aged between 61 to 70 years (38.50%) and the mean age was 63.79±10.36

Population based studies have shown a strong association between hypertension and LVH. In fact in severe forms of hypertension there is a >50% incidence of LVH while in milder forms it is <25%. 2 The Framingham studies have also established an age linked prevalence of LVH. 3 Left ventricular hypertrophy (LVH) secondary to arterial hypertension is a complex cardiac phenotype resulting from the response of myocyte and non-myocyte components to mechanical and neuro-humoral stimuli. 4 Various studies have shown that LVH independently predicts morbidity and mortality. LVH predisposes to heart failure, ventricular tachyarrhythmia, atrial fibrillation, ischemic stroke, embolic stroke and sudden cardiac death. 5 The sensitivity of all the well-established ECG criteria to diagnose LVH is low and is in the range of 7-35% with mild LVH and only 10-50% with moderate to severe LVH whereas the overall specificity is >90%. 6 To improve the sensitivity of ECG to diagnose LVH we evaluated the novel Peguero-Lo Presti criteria which has shown higher sensitivity when compared to older well established criterion like Cornell voltage and Sokolow Lyon criteria

Materials and Methods:-
This one cross-sectional study was conducted in the Department of Cardiology of a tertiary care centre in North Karnataka from May 2017 to December 2017. Prior to the commencement of the study, ethical clearance was obtained from Human Ethics Committee.
A total of 400 patients aged above 30 years presenting with hypertension to the cardiology OPD who underwent ECG and 2D echocardiography were included in the study. Patients with myocardial infarction, valvular heart disease (Grade II or higher), valvular stenosis, LV dysfunction, pericardial disease, COPD, bundle branch blocks, atrial fibrillation or flutter were excluded from the study. The patients fulfilling selection criteria were informed in detail about the nature of the study and a written informed consent was obtained before enrolment.
Detailed history was obtained and thorough clinical examination was done and the findings were recorded on a predesigned and pretested proforma. All the patients underwent ECG and 2D echocardiography.
2D echocardiography:-Transthoracic echocardiography was used as a method of reference to estimate left ventricular mass. 7 All echocardiograms were recorded by a cardiologist. The LV was visualised with the patient lying in a modified left lateral decubitus position, with the ultrasound probe at the left parasternal window angled to visualise the heart in the long axis view. All the M-mode and 2D measurements were performed by the leading-edge-to-leading edge method, as described by the American Society of Echocardiography (ASE).
Left ventricular end-diastolic and end-systolic measurements were obtained with the patient in a partial left lateral decubitus position according to recommendations by the American Society of Echocardiography. 8,9 Frames with optimal visualization of interfaces and showing simultaneous visualization of the septum, left ventricular internal diameter, and posterior wall were used. Left ventricular mass was calculated by using the Devereux formula: left ventricular mass (g) ¼ 0.80 _ {1.04 _ [(septal thickness þ internal diameter þ posterior wall thickness)3 -(internal diameter)3]} þ 0.6 g. The left ventricular mass was indexed according to body surface area. LVH was defined as a left ventricular mass index >115 g/m 2 in male subjects and >95 g/m2 in female subjects. 10 ECG criterion:-A single electrocardiogram for every patient was obtained on the same day the echocardiogram was obtained. All 12-lead ECG interpretations were independently reviewed. Individual leads were analyzed by measuring the tallest R and the deepest S or QS complex in all the precordial and limb leads using the PR segment as baseline. In cases of voltage differences within the same lead, only the largest complex was selected. The Peguero-Lo Presti criteria was obtained by adding SD to the S amplitude in V4 (SD + SV4). Cutoff values of SD + SV4 ≥ 2.3 mV for female subjects and ≥2.8 mV for male subjects were considered positive for LVH based on the recent study by Peguero JG et al. In cases in which the SD was found in lead V4, the S wave amplitude was doubled to obtain the value SD + SV4.

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The Cornell voltage criteria was used as the main comparison given its reputation as the most accurate of the reported measurements. 11 The sex-specific Cornell voltage criteria was computed as the amplitude of R in aVL plus the amplitude of S or QS complex in V3 (RaVL + SV3) with a cutoff of >2.8 mV in men and >2.0 mV in women. 12 The Sokolow-Lyon voltage was obtained by adding the amplitude of S in V1 and the amplitude of R in V5 or V6 ≥ 3.5 mV (SV1 + RV5 or RV6); 13,14 Statistical analysis:-The categorical data was expressed as rates, ratios and percentages and comparison was done using chi-square test. Continuous data was expressed as mean ± standard deviation. The agreement between ECG criteria and 2d echocardiography was analysed with McNemar's test and a 'p' value of less than or equal to 0.05 was considered as statistically significant. The accuracy of Peguero-Lo Presti criteria for the assessment of LVH was determined by estimating sensitivity, specificity, positive predictive value and negative predictive value.

Results:-
In this study 73.5% of the patients were males with male to female ratio of 2.77:1 (Graph 1). Age ranged between 35 to 89 years and most of the patients were aged between 61 to 70 years (38.50%) and the mean age was 63.79±10.36 years (  (Table 4).

Discussion:-
The present study showed that, Peguero-Lo Presti criteria has higher sensitivity (54.17%), while maintaining higher specificity (91.35%) with higher diagnostic accuracy (73.50%) in the diagnosis of LVH among the patients with hypertension compared to the other two criterions that is Sokolow-Lyon criteria and Cornell Voltage criteria ( Table  5).
The Sokolow-Lyon criteria 14 has been evaluated in various studies to give sensitivity of 32%, 14 33%, 14 43%, 15 while in this study the sensitivity was 29.17% which was in agreement with the previous studies. The Cornell voltage criteria has been evaluated to give sensitivity of 41%, 16 and 28% 14 which was found to be 39.58% in the present study.
A retrospective study by Peguero JG et al. 17 in 2017 which devised the Peguero-Lo Presti criteria also reported sensitivity of 62% with specificity of 90% with strong agreement (p<0.011). The cut-off values determined by ROC obtained were ≥2.3 mV for females and ≥2.8 mv for males. In this study we used the same cut off values as that of Peguero JG et al. 17 and found higher sensitivity and specificity compared to other two criterions viz. Sokolow-Lyon and Cornell voltage criteria. 14 LVH is mainly determined by an increase in left ventricular mass, which can be estimated by the electrical voltage changes detected on the surface electrocardiogram. This principle makes the electrocardiogram an acceptable surrogate to detect changes in left ventricular mass. 17 The SD was the best single lead predictor of LVH in the studied cohorts. In fact, the sum of SD + SV4 in the studied population had a better diagnostic performance and showed nominally an improved performance over the traditional LVH. 17 However, the cardiac electrical voltage does not exclusively depend on the amount of myocardium. But, it is dependent on active and passive electrical properties of the heart and torsum. These in turn are modified by influencing factors such as distance of left ventricular cavity-electrode, the location of the surface electrode, individual antrophometric differences, conduction abnormalities, fibrosis of the myocardium, and lung pathology 18,19 In addition, it has been described that the ECG voltage may vary significantly from day to day, between patients, or even within the same patient. 13,20 All of these factors may attenuate the reproducibility of the test, leading to diagnostic errors. Given the aformentioned pitfalls, measurement of the maximum voltage increase in any single lead would be more sensitive in identifying an increase in the ventricular mass, rather than using any fixed lead criteria.
Overall the present study showed that, Peguero-Lo Presti criteria 17 has higher sensitivity and specificity in the ECG diagnosis of LVH compared to Sokolow-Lyon 14 and Cornell voltage criteria considering LV mass index by 2D Echocardiography as reference standard. However, these observations require further validation due to the potential limitations of this study that it is a single centre study and relatively smaller sample size. Another limitation is that the left ventricular mass and left ventricular mass index were estimated by using two-dimensional echocardiography and the main determinant of LVH in this study was the left ventricular mass. Though, echocardiography is known to have good reproducibility for the diagnosis of LVH and remains the most frequently used method in clinical practice. 21 It is reported that, 2D echocardiography ignores the hypertrophic rebuilding of myocardial tissue that occurs in early stages and may contribute to the discrepancies. 22