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We analysed the diagnostic performance of the signal-averaged QRS duration for the detection of left ventricular hypertrophy in 100 consecutive outpatients (62 men and 38 women; mean age, 49.8 +/- 11.8 years) with essential hypertension and compared the results with some of the currently employed electrocardiographic criteria. Forty-eight healthy subjects (24 men and 24 women; mean age, 46.4 +/- 12.1) with normal physical, electrocardiographic and echocardiographic findings served as a control group to derive normal reference values for signal-averaged QRS duration. Twenty-six (26%) hypertensives (22 men and 4 women) had left ventricular hypertrophy echocardiographically defined as a left ventricular massor = 261 g in men andor = 172 g in women or left ventricular mass indexor = 125 g/m2 in men andor = 112 g/m2 in women. The signal-averaged QRS duration was different in patients with than in those without left ventricular hypertrophy (102.1 +/- 10.8 vs. 95.8 +/- 8.4 ms; P0.01). Also, in the group with left ventricular hypertrophy QRS duration was longer, although not significantly different, in men than in women (103.5 +/- 10.7 vs. 94.2 +/- 8.8 ms; P n.s.). The correlation between the signal-averaged QRS duration and left ventricular mass was weak but statistically significant in men (r = 0.34; P0.05) in women (r = 0.30; P0.05) and in men and women together (r = 0.42; P0.01). Partition values of filtered QRS durationor = 114 ms in men andor = 107 ms in women were used to diagnose left ventricular hypertrophy as these values were above the upper limits in our control men and women when 95% confidence intervals were calculated. These criteria were insensitive (12%) but highly specific (99%) for left ventricular hypertrophy. The use of a single threshold value of filtered QRS durationor = 111 ms in both sexes combined improved sensitivity modestly (15%) while maintaining a good specificity (95%). Also, we tested the following standard electrocardiographic criteria: the Sokolow-Lyon index, the Romhilt-Estes point scoreor = 4 points andor = 5 points, the Cornell voltage criteria, the sum of QRS voltages in all 12 leads175 mm, and the QRS duration90 ms. Sensitivities ranged from 4% to 58% and specificities from 74% to 99%.(ABSTRACT TRUNCATED AT 400 WORDS)

We analysed the performance of the electrocardiogram in diagnosing left ventricular hypertrophy in 70 patients with isolated left anterior hemiblock and in 75 patients with right bundle branch block, either isolated (44 cases) or associated (31 cases) with left anterior hemiblock. Left ventricular hypertrophy defined as an echocardiographically determined left ventricular mass greater than 261 g in men and 172 g in women or left ventricular mass index greater than 125 g/m2 in men and 112 g/m2 in women was present in 48 subjects (57%) with isolated left anterior hemiblock and 33 subjects (44%) with right bundle branch block. In patients with isolated left anterior hemiblock the best results were obtained using the SV1 or SV2 + (RV6 + SV6) greater than 25 mm with 74% in sensitivity and 67% in specificity; the criterion SIII + (R + S) maximal in a precordial lead greater than or equal to 30 mm showed a sensitivity of 74% but a specificity of 47%. In the whole group of patients with right bundle branch block none of the criteria nor combination of criteria achieved an acceptable performance (sensitivities ranged from 17% to 41% and specificities ranged from 54% to 85%). When these patients were divided according to the presence or absence of concomitant left anterior hemiblock the electrocardiographic indexes mostly showed, in comparison to whole group, higher values in sensitivity and lower values in specificity in right bundle branch block plus left anterior hemiblock and an opposite behaviour in isolated right bundle branch block.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors prospectively studied the natural course of cardiac involvement and its relationship to cytosine-thymine-guanine (CTG) expansion in 50 patients with myotonic dystrophy who were submitted to periodic cardiovascular EKG and EKG-Holter monitoring during a median follow-up of 56 months. Nineteen patients (38%) developed major EKG changes. CTG length was not correlated with the frequency of EKG abnormalities, but was inversely correlated with the age at onset of EKG abnormalities (p < 0.0001). CTG length influences the timing of cardiac complications in myotonic dystrophy.

Atrial natriuretic hormone (ANH) concentrations were measured in 16 patients affected with myotonic dystrophy (MyD) undergoing 24-hour Holter ECG and in 15 age-matched normal subjects. Although the MyD patients did not show overt left ventricular function impairment, their plasma ANH levels were found to be higher (183.76 ± 113.25 pg/ml) compared to those of the control subjects (39.73 ± 9.95 pg/ml, p < 0.001). Nine patients with arrhythmias and some echocardiographic alterations formed subgroup A. Seven patients without cardiac alterations formed subgroup B. No significant difference in ANH emerged between the two subgroups. This evidence suggests that high plasma ANH levels in MyD cannot always be related to overt or latent heart failure and to arrhythmias.

We performed signal-averaged electrocardiography and 24-h ambulatory electrocardiographic monitoring in 53 patients with myotonic dystrophy to determine the incidence and clinical significance of ventricular late potentials. Patients were followed up for a mean period of 31 +/- 17 months (range 11-68 months). At entry, none of the patients had bundle branch block on 12-lead electrocardiogram and none had wall motion abnormalities on routine echocardiogram. Also, no patient had history of syncope or clinical evidence of ischemic heart disease or a documented sustained ventricular tachycardia. A group of 47 healthy subjects matched for age and sex also underwent signal-averaged electrocardiography for comparison with the patient group. Late potentials were diagnosed in the presence of at least two of the following measures: duration of the filtered QRS114 ms, root-mean-square voltage of the terminal 40 ms of the filtered QRS20 microV, and duration of the low-amplitude (40 microV) signals of terminal filtered QRS38 ms. Late potentials were more frequent in patients than in controls: 18 of the 53 patients (34%) showed late potentials compared with four of the 47 controls (8.5%) (P0.01). In 45 patients (85%) no ventricular ectopy (40 cases) or infrequent premature ventricular complexes (five cases) were detected on Holter monitoring. Complex ventricular arrhythmias were traced in the remaining eight patients. These were six of the 18 patients with, and two of the 45 patients without late potentials (33% vs. 6%, respectively; P0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

We performed exercise testing, 24-h ambulatory blood pressure monitoring and echocardiography in 37 selected patients with borderline hypertension (24 men and 13 women, mean age 39.8 years, range 23-50) in an attempt to detect early cardiovascular changes that could predict future established hypertension. All subjects were clinically reinvestigated after a mean period of 28 +/- 4 months. At entry 24/37 (65%) showed an exaggerated blood pressure response to exercise (systolic pressureor = 220 mmHg and/or diastolic pressureor = 105 mmHg) while 13 (35%) had a normal pressure response. Patients with exaggerated pressure response showed significantly higher left ventricular mass index in comparison to those with normal pressure response (98.1 +/- 10.7 vs. 84 +/- 13, respectively; P0.05). They also had higher, although not significantly different, average 24-h systolic and diastolic blood pressure levels. At follow up seven subjects (16%) were diagnosed as having established hypertension, while 30 (84%) remained borderline hypertensives. No subject was judged normotensive. All of the seven hypertensive subjects were a proportion (7/24 = 29%) of the group with exaggerated blood pressure response to exercise. Also, they were the eldest of the total group of borderlines (mean age 44 years) and had the highest left ventricular mass index (100.6 +/- 13 g/m2). Borderline hypertensives show a spectrum of cardiovascular changes that could be considered as a part of the hypertensive risk profile. However, there are no specific characteristics that reliably distinguish subjects prone to develop hypertension. Repeated clinical observations and correct measurements of resting blood pressure may have greater relevance in the management of patients with borderline hypertension.

There is a large body of evidence that the electrocardiogram (ECG) is insensitive in the recognition of left ventricular hypertrophy (LVH), in comparison with the echocardiogram; however, its specificity is high. In this study we further analyzed the performance of the ECG in detecting LVH in 200 consecutive patients (124 men and 76 women, mean age 50.9 years) with mild to moderate essential hypertension, using echocardiographically determined left ventricular mass (LVM) as the standard for comparison. To test the hypothesis that, owing to the high number of true positive findings, the ECG may still be useful for clinical purposes by selecting subsets of hypertensives with higher degrees of LVH, we compared the mean values of LVM index corresponding to either positive (true positive) or negative (false negative) electrocardiographic signs of LVH. In this study 69 patients (34.5%) had echocardiographic LVH, as defined by a LVM index exceeding 125 g/m2 for men and 112 g/m2 for women. Almost all criteria demonstrated high levels of specificity (or = 89%). In the whole group the Lewis index ((RI - RIII)+(SIII - SI)or = 17 mm) showed a slight superiority in diagnosing LVH (sensitivity = 43%) in comparison to the remaining criteria; the confidence intervals estimate of sensitivities confirmed such diagnostic superiority only with respect to those criteria with a sensitivityor = 17%. However, the use of McNemar's test to compare sensitivities of all electrocardiographic criteria at matched specificities (or = 95%) did not show significant differences (P.05).(ABSTRACT TRUNCATED AT 250 WORDS)

We studied 122 relatives (18 parents, 33 siblings, 57 offspring, 10 nephews and 4 nieces; mean age 34 +/- 19 years) of 33 patients with hypertrophic cardiomyopathy (HC) to analyze the incidence and clinical significance of electrocardiographic and echocardiographic abnormalities. On the basis of conventional echocardiographic criteria 12 first-degree relatives were considered to be affected by HC. Thirteen first-degree relatives and 1 niece were judged as having probable but not definite HC, i.e. left ventricular (LV) wall thicknesses over the 95% upper limit of confidence interval for age and body surface area or borderline ventricular septal thickness but a septal-to-free wall thickness ratioor = 1.3 in the absence of an identifiable origin. Ninety relatives had normal echocardiographic findings. The remaining 6 subjects were found to have essential hypertension and were therefore excluded from consideration. Electrocardiogram (ECG) showed major or minor abnormalities in all relatives with HC, in 7 of the 14 probably affected by HC and in 20 of the 90 with normal echocardiogram. Of the 122 relatives 44 (38 with normal echocardiogram and 6 probably affected by HC) were reexamined over a mean period of 4.3 years (range 2-7). In the course of the follow-up 3 subjects modified their cardiac status. Two offspring who had at entry LV hypertrophy at ECG as isolated cardiac abnormality developed HC over a period of 5 years. A sibling who had only minor electrocardiographic abnormalities in the first study became probably affected by HC 3 years later.(ABSTRACT TRUNCATED AT 250 WORDS)

We assessed the reliability of multiple electrocardiographic variables for detecting left ventricular hypertrophy in 100 patients (aged 23 to 92 years, mean age 39 +/- 14) with complete left bundle branch block and different underlying cardiac diseases. Left ventricular hypertrophy, defined as an echocardiographically evaluated left ventricular mass greater than 241 g, was present in 66 of the 100 patients. The electrocardiographic parameters with the highest sensitivity were both the Cornell voltage criteria (RaVL + SV3 greater than 28 mm in men and greater than 20 mm in women) and the combination of criteria proposed by Kafka (any of these four indexes: RaVL greater than or equal to 11 mm, QRS axis -40 degrees or less, SV1 + RV5 or RV6 greater than or equal to 40 mm, SV2 greater than or equal to 30 mm and SV3 greater than or equal to 25 mm), with a sensitivity of 77%. Both criteria had a very low specificity (32 and 35%, respectively). The high specificities (greater than or equal to 88%) of several electrocardiographic criteria were accompanied by ineffective low sensitivities (less than 35%). Moreover, the cumulative parameters of Kafka and Cornell voltage criteria achieved a sensitivity of 84 and 89%, respectively, in hypertensive patients and in those with valvar diseases. None of the electrocardiographic indexes tested showed a significant difference in sensitivity when applied in categories of patients with left ventricular hypertrophy and different left ventricular geometry (cavity dilation or concentric hypertrophy). These data indicate that both conventional and recently proposed electrocardiographic criteria for left ventricular hypertrophy in the presence of left bundle branch block poorly recognize an augmented left ventricular mass.

To determine the independent effects of left bundle branch block (LBBB) on global and regional left ventricular (LV) function we performed equilibrium radionuclide angiocardiography at rest in 3 patients with chronic LBBB (group I, mean age 53.6 years and in 6 patients with intermittent LBBB (group II, mean age 41.5 years). All patients were judged to have an apparently normal heart. In 2 of 3 patients of group I a LV ejection fraction lower than 50% was observed, and in all 3 patients septal motion abnormalities were present. In all patients of group II the global LV ejection fraction was normal during normal conduction and decreased during LBBB; the inferoapical regional ejection fraction decreased in 5 of 6 cases and the posterolateral regional ejection fraction in 3 of 6 cases. Moreover, septal hypokinesis was observed both during normal and abnormal conduction in all group II patients. These findings seem to confirm that LBBB, chronic or intermittent, is able to deteriorate LV performance at rest, even in patients with an otherwise normal heart.

Ambulatory electrocardiographic monitoring (AEM) was performed in 22 patients (range 13-62 years; mean age 38.2 +/- 12.7) with grades I, II and III of myotonic dystrophy in order to evaluate the occurrence of potentially dangerous cardiac arrhythmias and conduction disturbances. All patients had previously undergone echocardiographic examination to determine whether structure and function abnormalities were present. In 6 patients with normal resting electrocardiogram, AEM revealed: first degree A-V block (4 cases), class IVa Lown ventricular arrhythmias (3 cases) and episodes of atrial fibrillation (4 cases). In 2 of 3 cases with abnormal scalar electrocardiogram new abnormalities (first degree A-V block and further prolongation of P-R interval) were demonstrated by AEM. Only 1 patient had mild signs of left ventricular dysfunction at echo. Disorders of cardiac conduction and rhythm are characteristic of myotonic dystrophy and can predispose to severe cardiac events. In this respect AEM is shown to be an early and sensitive tool in identifying patients at risk.

Antimitochondrial autoantibodies (AMA) were tested by indirect immunofluorescence in three groups of subjects with different types of myocardial hypertrophy: 35 patients affected with hypertrophic cardiomyopathy (HC), 20 patients with cardiac hypertrophy secondary to essential hypertension, and 35 active endurance athletes with exercise-induced left ventricular hypertrophy. Forty-two healthy subjects served as a control group. Left ventricular hypertrophy was considered a left ventricular mass (LVM) echocardiographically calculated (Devereux formula), exceeding 244 gm or a LVM index exceeding 122 gm/m2 (greater than 2 SD from a previously studied normal population). AMA were found in 15 of 35 (43%) patients with HC and in 6 of 20 (30%) patients with hypertensive heart disease (p less than 0.01); in contrast, AMA were not present in the sera of athletes or in the sera of controls. Although the significance of AMA in subjects with pathologic myocardial hypertrophy has not yet been established, their absence in the sera of athletes strengthens the opinion that cellular changes, as a compensatory response of the myocardium to a work overload, have a physiologic fashion in these cases. Moreover, identification of AMA in the sera of athletes with disproportionate severe left ventricular hypertrophy of uncertain origin may be helpful to ensure a single diagnosis.

In this study we noninvasively followed for a mean period of 46 months 21 patients with different grades of myotonic dystrophy to evaluate the course of the involvement of the cardiac conducting system. Six patients (28.6%), 1 affected by a mild and 5 by a severe form of the neuromuscular disorder, showed appearance or deterioration of conduction disturbances suggesting a serious derangement of the specialized tissue; in 3 of them a permanent demand pacemaker was implanted. Conduction defects are the most frequent cardiac manifestations in myotonic dystrophy and become worse with time, mainly in patients with higher degrees of the disease. Furthermore, first-degree atrioventricular block may represent an early sign of developing of more advanced conduction defects.

To determine the occurrence of familial and sporadic forms of hypertrophic cardiomyopathy (HC) 74 first-degree relatives of 21 patients with proven HC were studied by M-mode and two-dimensional echocardiography. A diagnosis of HC was made in 11 relatives (15%) while it was excluded in 61 of them (82%); 2 subjects (3%) were considered neither affected nor unaffected (borderline left ventricular hypertrophy suggestive of HC). Inspection of pedigrees revealed 38% of familial forms of HC with an autosomal dominant pattern of inheritance in 5/8 families (62%). Furthermore, among those relatives judged unaffected by means of full echocardiographic criteria for HC, an attempt was made to find out whether minor changes of left ventricular geometry were present for their possible implications in genetics of HC (latent or potential forms, low phenotypic expression of the disease). Eleven out of 61 unaffected relatives had a left ventricular wall thickness radius ratio greater than 0.50 (equivocal hypertrophy), a value that was higher than two standard deviations of the control group. Assessment of clinical significance of borderline and equivocal hypertrophy in relatives of patients with HC is required for a better understanding of genetic transmission of this disease. In this view the occurrence of sporadic and familial forms of HC might be revisited.

We utilized Doppler echocardiography to characterize left ventricular diastolic function in 42 patients with myotonic dystrophy (mean age 37 +/- 12 years, 64% male) who had no symptoms of heart failure and had normal left ventricular systolic function. Data were compared with those in 41 normal control subjects of similar age and gender. Heart rate, systemic blood pressure, and cardiac dimensions (wall thickness, left atrial and left ventricular cavity dimensions) were similar and not significantly different in patients and controls. As a group, patients showed significantly increased deceleration time and decreased rate of decline of flow velocity in early diastole (p0.0001 and p0.01, respectively) when compared to controls. Individual patient analysis showed that 10 (24%) of the 42 patients with myotonic dystrophy had 2 or more abnormal Doppler indexes of diastolic function consistent with a pattern of impaired left ventricular relaxation. The most common abnormalities were increased deceleration time (224 ms; 9 patients), prolonged isovolumic relaxation time (103 ms; 8 patients) and reduced rate of decline of flow velocity in early diastole (2.1 m/s2; 5 patients). In addition, peak early diastolic flow velocity was reduced (43 cm/s) in 3 patients and early to atrial peak flow velocity ratio was reduced (1) in 2 patients. Comparison of subgroups of patients with and without abnormal Doppler indexes showed no significant differences with regard to age, gender, heart rate, systemic blood pressure, severity of neuromuscular disease, and cardiac dimensions. After study, patients were clinically followed up for a mean period of 20 +/- 7 months (range 12-35). During observation no patients died and none experienced symptoms of heart failure. This Doppler echocardiographic analysis demonstrates that diastolic abnormalities may be present in patients with myotonic dystrophy, even in the absence of symptoms of cardiac failure or left ventricular systolic dysfunction. These diastolic abnormalities suggest an intrinsic myocardial abnormality in patients with myotonic dystrophy; however, whether they represent a preclinical phase of myocardial involvement or an intrinsic feature of the primary myocardial disease process in myotonic dystrophy remains to be elucidated.