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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 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 (p < 0.0001 and p < 0.01, 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.

Background: In patients with myotonic dystrophy, histopathological and electrophysiologic abnormalities of cardiac conduction system may lead to sudden cardiac death due to atrioventricular block or to ventricular electrical instability., Methods: Four members of a family affected by myotonic dystrophy are reported, which underwent a cardiological examination including invasive electrophysiological study and prolonged follow-up. Other 3 members of the same family had died suddenly. No clinical data are available for 2 of these patients, while paroxysmal atrial flutter and non sustained ventricular tachycardia had been detected at Holter in the third one., Results: Signs of atrioventricular conduction impairment, poorly predictable with non invasive electrocardiography, were found in the 4 patients undergoing intracardiac electrophysiologic study. In 2/4 patients, both having dizzy spells and the most impaired atrioventricular conduction, a pace-maker was implanted. Polymorphic, non sustained ventricular response was induced in 2/4 patients, 1 of them with spontaneous high grade ventricular arrhythmias., Conclusions: The respective role of atrioventricular conduction impairment and ventricular vulnerability in determining sudden death has not been stated so far in these patients. The observed polymorphic non sustained response should not be "a priori" disregarded as aspecific, since it could be the electrophysiological counterpart of a peculiar anatomic arrhythmogenic substrate. A comprehensive study, including invasive electrophysiology, is advisable in all patients with myotonic dystrophy whenever a member of their family presents with cardiac involvement, to assess the most probable life-threatening arrhythmogenic mechanism.

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 QRS > 114 ms, root-mean-square voltage of the terminal 40 ms of the filtered QRS < 20 microV, and duration of the low-amplitude (< 40 microV) signals of terminal filtered QRS > 38 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%) (P < 0.01). 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; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Background: In the early 1980s, studies performed in highly selected referral patients with hypertrophic cardiomyopathy reported a strong association between the presence of brief episodes of ventricular tachycardia (VT) on ambulatory ECG monitoring and sudden death. These observations led to antiarrhythmic treatment in many patients with hypertrophic cardiomyopathy and brief episodes of VT. In recent years, however, a growing awareness of the potential arrhythmogenic effects of antiarrhythmic medications has raised doubts regarding such a therapeutic approach, particularly in less selected and lower-risk patient populations., Methods and Results: In the present study, we examined the prognostic significance of nonsustained VT in a population of 151 patients with hypertrophic cardiomyopathy who were asymptomatic or had only mild symptoms at the time of their initial ambulatory ECG recording. Of the 151 study patients, 42 had episodes of VT and 109 did not. The runs of VT ranged from 3 to 19 beats, with 35 patients (83%) having < 10 beats. The number of runs of VT ranged from 1 to 12 in 24 hours, with 36 patients (86%) having < or = 5 episodes of VT. Thus, in most patients, the episodes of VT were brief and infrequent. Follow-up averaged 4.8 years. Of the 151 study patients, 6 died suddenly, 3 in the group with VT and 3 in the group without VT. Two other patients, both in the group without VT, died of congestive heart failure. The total cardiac mortality rate was 1.4% per year in the patients with VT (95% CI, 0.4% to 3.5%) and 0.9% in those without VT (95% CI, 0.4% to 2.0%; P = .43). The relative risk of cardiac death for patients with VT was 1.4 compared with patients without VT (95% CI, 0.6 to 6.1). The sudden death rate was 1.4% per year in the patients with VT (95% CI, 0.4% to 3.5%) and 0.6% in those without VT (95% CI, 0.2% to 1.5%; P = .24). The relative risk of sudden death for patients with VT compared with those without VT was 2.4 (95% CI, 0.5 to 11.9). Of the 151 patients included in the study, 88 (58%) remained asymptomatic and were not treated with cardioactive medications during follow-up. Of these 88 patients, 20 were in the group with VT and 68 in the group without VT. None of these patients died., Conclusions: Our results show that cardiac mortality is low in patients with hypertrophic cardiomyopathy who are asymptomatic or only mildly symptomatic and have brief and infrequent episodes of VT on ambulatory ECG monitoring. Our findings also suggest that brief and infrequent episodes of VT should not be considered, per se, an indication for antiarrhythmic treatment in such patients.

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 mass > or = 261 g in men and > or = 172 g in women or left ventricular mass index > or = 125 g/m2 in men and > or = 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; P < 0.01). 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; P < 0.05) in women (r = 0.30; P < 0.05) and in men and women together (r = 0.42; P < 0.01). Partition values of filtered QRS duration > or = 114 ms in men and > or = 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 duration > or = 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 score > or = 4 points and > or = 5 points, the Cornell voltage criteria, the sum of QRS voltages in all 12 leads > 175 mm, and the QRS duration > 90 ms. Sensitivities ranged from 4% to 58% and specificities from 74% to 99%.(ABSTRACT TRUNCATED AT 400 WORDS)

We analyzed the performance of the electrocardiogram in the diagnosis of left atrial enlargement in 1000 unselected consecutive patients (585 men and 415 women, mean age 46 +/- 17 years) with different cardiovascular diseases or clinically normal. Echocardiography was used as reference method to assess left atrial dimension. The following electrocardiographic criteria were considered: total P-wave duration in leads D1, D2 or D3 > or = 110 ms; P terminal force in lead V1 equal to or more negative than -0.04 mm-s, and P-wave notching in leads D1, D2 or D3 with a peak to peak interval > or = 40 ms. A total of 89 subjects (8.9%) fulfilled the echocardiographic criteria for left atrial enlargement, defined as a left atrial dimension above the upper limit of the normal 95% predicted interval calculated as a function of age and body surface area. In the whole group 67 subjects (6.7%) had at least one of the electrocardiographic criteria for left atrial enlargement. In only 23 patients there was agreement between electrocardiogram and echocardiogram in the diagnosis of left atrial enlargement. The three electrocardiographic indexes had specificity > or = 97%, however sensitivity was unacceptable (< or = 18%). Negative predictive value was high (> or = 91%) but positive predictive value was poor (< or = 35%).(ABSTRACT TRUNCATED AT 250 WORDS)

In this paper we proposed the use of a spectral analysis technique, the fast Fourier transform (FFT), for the evaluation of the normal circadian blood pressure rhythm. By means of this algorithm it is possible to separate the slower and reproducible variations of the blood pressure profile (probably due to endogenous rhythm) from the faster and random ones (due to psychophysical status of the subject). The FFT technique is used for the analysis of ambulatory blood pressure monitorings obtained in 66 normotensive subjects (38 males and 28 females, mean age 35 +/- 10 years). Taking into account the mean duration of pressure variations related to major daily activities (e.g. sleeping, eating, etc) it is proposed to consider the first 10 harmonics as those having the main influence on the circadian blood pressure rhythm. The amplitude of the first 10 harmonics of the whole sample was evaluated by using the chi 2 and the Kolmogorov tests, and the results confirmed the assumption of a normal distribution of the amplitudes. The 95% confidence interval of these harmonics was chosen as the criteria for defining a normal range for the circadian blood pressure rhythm. This approach was tested in a group of 4 hypertensive patients showing that alteration of the circadian blood pressure rhythm can be easily diagnosed.

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 pressure > or = 220 mmHg and/or diastolic pressure > or = 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; P < 0.05). 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.

Myotonic dystrophy is an autosomal dominant disease affecting many organ systems, including the heart. Abnormalities of the cardiac conduction system are a frequent and well-documented finding in this neuromuscular disease, whereas overt signs of heart failure are rarely reported. However, controversy exists about the prevalence of preclinical left ventricular (LV) dysfunction in patients with myotonic dystrophy who have no symptoms of heart failure. To address this issue, load-independent LV function indexes were compared in patients with myotonic dystrophy and in normal subjects. LV measurements were obtained with M-mode echocardiography in 43 consecutive patients with myotonic dystrophy (mean age 35 +/- 14 years) who had no clinical evidence of heart failure, and in 35 sex- and age-matched controls. A cuff sphygmomanometer was used to determine blood pressure. No difference was found between patients and control subjects in the percentage of LV ejection fraction predicted for end-systolic stress (103 +/- 7 vs 103 +/- 7%; p = 0.97) or in the end-systolic stress/volume index ratio (2.9 +/- 0.5 vs 2.7 +/- 0.4 dyne7/cm3; p = 0.09). Similarly, no significant difference in LV myocardial function was detected between the 19 patients with a mild degree of the neuromuscular disease and in the 24 with a moderate or severe degree of the disease. Finally, LV myocardial function was compared between patients with myotonic dystrophy and atrioventricular or intraventricular conduction disturbances (n = 8) and those without these disturbances (n = 35), but no significant difference in the percentage of LV ejection fraction predicted for end-systolic stress or in the end-systolic stress/volume index ratio could be detected.(ABSTRACT TRUNCATED AT 250 WORDS)

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 sensitivity < or = 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 ratio > or = 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 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)

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.

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.

The Authors report the significant progress that has been made in the past few decades in defining the connections between the central nervous system and the cardiovascular system and the mechanisms by which neuroadrenergic influences over cardiac function can lead to heart disease. Moreover, the question of sudden cardiac death, particularly in individuals without a prior history of clinical heart disease, is analysed in the light of present knowledge concerning the deleterious effects on cardiac electrophysiologic properties of psychosocial and behavioural factors.

Current knowledge and assumptions about inherited cardiovascular diseases are reported in this review. They are examined from two different points of view. In the first section (familial cardiovascular diseases) discussion will center on the main cardiovascular diseases that have a definite clinical and pathophysiological feature in which familial occurrence has been extensively demonstrated. The genetic aspects of the primary cardiomyopathies, mitral valve prolapse, arrhythmias and conduction disturbances, long QT syndromes and abnormalities of ventricular repolarization, cardiovascular malformations, coronary artery disease, essential hypertension and rheumatic fever will be examined. In the second section (cardiovascular involvement in genetic disorders) discussion will be confined to the inherited multisystem disorders involving the cardiovascular system that most frequently occur in clinical practice. Currently known cardiovascular findings in relationship to chromosomal aberrations, connective tissue disorders, metabolic and enzymatic disorders, neuromuscular disorders and other rarer syndromes will be reported.