Patients with hypertrophic cardiomyopathy at risk for paroxysmal atrial fibrillation: advanced echocardiographic evaluation of the left atrium combined with non-invasive P-wave analysis.

AIMS: The maintenance of sinus rhythm is crucial for the functional capacity of patients with hypertrophic cardiomyopathy (HCM). Using a multimodality approach, we attempted to identify potential predictors of paroxysmal atrial fibrillation (PAF) in HCM patients. METHODS AND RESULTS: Thirty HCM patients (17 males, mean age 57.9 ± 13.6) with at least one documented PAF episode and 32 age- and sex-matched HCM control patients as well as 25 healthy volunteers were studied in sinus rhythm. Study subjects underwent 2D echocardiography including a colour Doppler myocardial imaging evaluation of the left atrium (LA). Additionally, an orthogonal electrocardiogram was acquired; P-wave duration, maximum, and mean energies were calculated for each subject at each orthogonal lead and the composite vector axis using the Morlet wavelet analysis. Compared with HCM controls, in HCM-PAF patients, LA antero-posterior diameter was significantly enlarged (LADAP: 46.1 ± 5.9 vs. 40.0 ± 4.7 mm, P < 0.001), peak strain rate of the LA lateral wall in the reservoir phase was significantly decreased (LAT peak SR-S: 1.93 ± 0.51 vs. 2.55 ± 0.83 s(-1), P < 0.01), and P-wave duration in the Z-lead was significantly prolonged (P-durZ: 106.9 ± 24.6 vs. 86.2 ± 14.3 ms, P < 0.001). Cut-off values and areas under the curve (AUCs) for individual parameters were 42.0 mm, 2.32 s(-1), and 98.8 ms and 0.81, 0.74, and 0.78, respectively. A multivariable model combining LADAP, LAT peak SR-S and P-durZ had an AUC of 0.90, a sensitivity of 0.87, and a specificity of 0.91 for identifying PAF patients. CONCLUSION: P-wave duration combined with LA antero-posterior diameter and myocardial deformation indices resulted in a higher power for discriminating HCM-PAF patients, when compared with individual parameters derived from either wavelet analysis or 2D echocardiography.

Chronotropic incompetence and its relation to exercise intolerance in hypertrophic cardiomyopathy.

BACKGROUND: Diminished functional capacity is common in hypertrophic cardiomyopathy (HCM), although the underlying mechanisms are complicated. We studied the prevalence of chronotropic incompetence and its relation to exercise intolerance in patients with HCM. METHODS: Cardiopulmonary exercise testing was performed in 68 patients with HCM (age 44.8 ± 14.6 years, 45 males). Chronotropic incompetence was defined by chronotropic index (heart rate reserve)/(220-age-resting heart rate) and exercise capacity was assessed by peak oxygen consumption (peak Vo(2)). RESULTS: Chronotropic incompetence was present in 50% of the patients and was associated with higher NYHA class, history of atrial fibrillation, higher fibrosis burden on cardiac MRI, and treatment with ß-blockers, amiodarone and warfarin. On univariate analysis, male gender, age, NYHA class, maximal wall thickness, left atrial diameter, peak early diastolic myocardial velocity of the lateral mitral annulus, history of atrial fibrillation, presence of left ventricular outflow tract obstruction (LVOTO) at rest, and treatment with beta-blockers were related to peak Vo(2). Peak heart rate during exercise, heart rate reserve, chronotropic index, and peak systolic blood pressure were also related to peak Vo(2). On multivariate analysis male gender, atrial fibrillation, presence of LVOTO and heart rate reserve were independent predictors of exercise capacity (R(2) = 76.7%). A cutoff of 62 bpm for the heart rate reserve showed a negative predictive value of 100% in predicting patients with a peak Vo(2) <80%. CONCLUSIONS: Blunted heart rate response to exercise is common in HCM and represents an important determinant of exercise capacity.

Prevalence and clinical outcomes of incidentally diagnosed hypertrophic cardiomyopathy.

The purpose of the present study was to evaluate the prevalence and prognosis of patients incidentally diagnosed with hypertrophic cardiomyopathy (HC). We studied 380 consecutive patients with HC (49.3 +/- 17.2 years; 65% men) for a median of 58 months (range 6 to 454). The patients were divided into 2 groups: those incidentally diagnosed from routine examination findings (precordial murmur and/or abnormal electrocardiographic findings) and those diagnosed either because of symptomatic status or by screening because of a family history of HC. Those patients who had been incidentally diagnosed constituted 29.2% of our study cohort. Although overall mortality did not differ between the 2 groups (p = 0.12), the patients diagnosed either because of symptoms or a family history tended to have at least a 4.5-fold greater risk of cardiovascular death (relative risk 4.5, 95% confidence interval 1.04 to 19.6, p = 0.04) and a 4.22 greater risk of sudden death (relative risk 4.22, 95% confidence interval 1.0 to 18.22, p = 0.04). Despite the greater sudden death mortality among the nonincidentally diagnosed patients, no statistically significant difference was found concerning the sudden death risk factor frequency (p = 0.96) between the 2 groups. In conclusion, the discrepancy between the low numbers of patients reported by published registries and the relatively high prevalence of the disease in the general population can be attributed to the large number of patients who remain asymptomatic, even throughout their life, awaiting an accidental diagnosis. Those patients with an incidental diagnosis have a more benign course, as shown by the total cardiovascular and composite sudden death mortality. A high level of awareness and suspicion for HC among physicians is essential for clinical recognition of such patients.

Left ventricular outflow tract obstruction as a risk factor for sudden cardiac death in hypertrophic cardiomyopathy.

The effect of left ventricular outflow tract obstruction (LVOTO) at rest on the incidence of sudden death (SD) in patients with hypertrophic cardiomyopathy is rather conflicting. The aim of this study was the evaluation of LVOTO at rest as a new potential risk factor for SD in hypertrophic cardiomyopathy. A total of 166 patients (112 men, 51.8 +/- 15.6 years) were studied; 50 patients (30.1%) had peak instantaneous LVOTO gradients of > or = 30 mm Hg at rest. During the follow-up period (median 32.4 months, range 1 to 209), 13 patients either died suddenly, or had cardiac arrest, documented sustained ventricular tachycardia, or implantable cardioverter defibrillator discharge. The cumulative event-free survival rate was 92% in patients with LVOTO, and 92% in patients without obstruction (p = NS). LVOTO at rest was associated with a particularly low positive predictive value for SD (8%), although a high negative predictive value (92%) was recorded. Patients having syncope or presenting with a maximum wall thickness > or =3 cm in echocardiography were more sensitive to SD emergence because they had a 13.07 (95% confidence interval 4.00 to 46.95, p <0.0001) and a 10.07 (95% confidence interval 2.92 to 34.79, p = 0.003) greater relative risk, respectively. In conclusion, our cohort study results do not support LVOTO as an independent risk factor for SD in patients with hypertrophic cardiomyopathy.

Indications for permanent pacing and pacing mode prescription from 1989 to 2006. Experience of a single academic centre in Northern Greece.

INTRODUCTION: Indications for pacing and pacing mode prescription have changed in the past decades following advances in pacemaker technology. The aim of the present study was to evaluate changes in indications for pacing and pacing modes during the years 1989-2006 in a single academic pacemaker centre in Northern Greece. METHODS: Archives of permanent pacemaker implantation procedures were studied retrospectively and data from all implants, first or replacements, were retrieved. RESULTS: Data from 2078 procedures were found, 78.7% of which were first implantations. Patients were 54% male with mean age 72.5 years. Main indications for pacing were atrioventricular block (AVB, 45.7%), sick sinus syndrome (SSS, 32.8%), and atrial fibrillation (12.1%). Almost half (48.9%) of the AVB cases were complete AVB, while the most common types of SSS were tachy-brady syndrome (44.1%) and asystole (27.1%). Rare indications for pacing were carotid sinus syndrome (5.0%), heart failure (3.3%) and hypertrophic obstructive cardiomyopathy (1.0%). The two most frequently used pacing modes were VVI (38.5%) and DDD (25.8%). However, pacing modes have changed greatly over the years, with a marked increase in dual-chamber pacing after 1997 and a preference for rate responsive units after 2002. Biventricular systems were also used in selected patients with heart failure from 2002 on. CONCLUSIONS: Indications for pacing and pacing mode prescription in our centre are similar to other pacemaker registries and reflect the global trend in pacing for mimicking the physiological activity of the heart and for addressing problems other than symptomatic bradycardia.

Hypertrophic cardiomyopathy with late enhancement of the non-hypertrophied left ventricular segments.

A 56-year-old asymptomatic man was referred for further evaluation because he displayed a rapid T-wave change on the ECG, from positive T waves to giant negative T waves in the anterolateral precordial leads, within 2 years. Transthoracic echocardiography revealed mild left ventricular apical hypertrophy without obstruction. Cardiac magnetic resonance imaging showed apical hypertrophic cardiomyopathy with focal hyperenhancement of the non-hypertrophic basal lateral segment of the left ventricle and absence of hyperenhancement of the hypertrophied apical segments.

Right ventricular function in ischemic or idiopathic dilated cardiomyopathy.

BACKGROUND: Differentiation between ischemic (ICM) and dilated cardiomyopathy (DCM) has important therapeutic implications because the former may benefit from coronary revascularization. The aim of this study was to investigate right ventricular (RV) function using tissue Doppler echocardiography (TDE) and compare the TDE parameters of the RV among patients with ICM and DCM. METHODS AND RESULTS: Forty-two patients with ICM and 40 patients with DCM were studied with conventional echocardiography and TDE. The 2 groups did not differ in terms of New York Heart Association class, left ventricular ejection fraction and pharmacological treatment. Patients with ICM had higher pulmonary artery systolic pressure (44.4 mmHg vs 34.7 mmHg, p=0.006) and lower tricuspid annular motion systolic (RV Sa 0.06 m/s vs 0.09 m/s, p<0.0001), and diastolic velocities (RV Ea 0.05 m/s vs 0.07 m/s, p=0.0003, RV Aa 0.075 m/s vs 0.11 m/s, p=0.0016). They also exhibited a higher ratio of early transtricuspid filling velocity to early diastolic velocity of the tricuspid annulus (RV E/Ea 8.2 vs 5.7, p=0.0008). Age, pulmonary artery systolic pressure and tricuspid Sa were significant independent predictors of the diagnosis of ICM. CONCLUSIONS: RV dysfunction is more pronounced in patients with ICM than in patients with DCM. The RV TDE parameters can be used to complement clinical and conventional echocardiographic findings in the assessment of patients with ICM and DCM.

Prognostic significance of right ventricular diastolic function in thalassaemia major.

While left ventricular (LV) restrictive filling pattern is an ominous echocardiographic finding in thalassaemia major (TM), the prognostic significance of right ventricular (RV) diastolic function in patients with TM has not been thoroughly investigated. We studied 45 TM asymptomatic transfusion-dependent patients with normal LV systolic function by Doppler echocardiography. The 15-year cumulative survival rate was 34% in patients with RV restrictive filling pattern (RFP) and 82% in patients with RV non-RFP (log-rank = 10.41, p = 0.0013). Doppler estimation of RV filling pattern is very important in evaluating the prognosis of TM patients and should be performed routinely and using a standardised followup protocol.

Impact of autonomic neuropathy on left ventricular function in normotensive type 1 diabetic patients: a tissue Doppler echocardiographic study.

Cardiovascular autonomic neuropathy (CAN) is one of the most serious complications of diabetes and has been weakly linked with left ventricular (LV) diastolic dysfunction. Previous studies that explored this association either suffer from inadequate definition of CAN or have mainly used conventional Doppler or nuclear techniques to investigate LV diastolic function. Tissue Doppler imaging (TDI) has evolved as a new quantitative tool for the assessment of cardiac systolic function, diastolic function, and the hemodynamics of LV filling. We sought to investigate conventional and TDI-derived indexes of LV systolic and diastolic function in type 1 diabetic patients with and without CAN and also in normal control subjects. Our findings suggest that the presence of CAN seems to have an additive effect on LV diastolic dysfunction in type 1 diabetes.

Clinical significance of tissue Doppler imaging in patients with hypertrophic cardiomyopathy.

BACKGROUND: A transmitral E/septal Ea ratio > or =15 is a predictor of adverse outcome in cardiac disease, so it was hypothesized that a septal E/Ea >/=15 would predict the risk of adverse outcome, including sustained ventricular tachycardia (VT), cardiac arrest, implantable cardioverter defibrillator (ICD) discharge, or sudden death (SD) in patients with hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: The study group comprised 96 consecutive patients with HCM (median age 53 years) who completed all noninvasive tests for risk stratification. The endpoint of the study was defined as death, cardiac arrest, documented sustained VT, or ICD-discharge. The median follow-up was 20.6 months. All patients were alive at the end of follow-up, although 8 patients had reached the endpoint during the study period. The variables that were predictive of adverse clinical outcome were family history of premature SD (p=0.03), syncope (p<0.001), maximum wall thickness > or =3 cm (p=0.02), and septal E/Ea > or =15 (p<0.001). In a stepwise multivariable model the only independent prognostic indicator was a septal E/Ea > or =15 (relative risk 0.26, 95% confidence interval 0.2-0.58, p<0.001). The cumulative event-free survival rate was 78.9% in patients with septal E/Ea > or =15, and 100% in patients with septal E/Ea <15 (p=0.0003). CONCLUSIONS: Septal E/Ea > or =15 predicts patients with HCM who are at risk of sustained VT, cardiac arrest, ICD-discharge, or SD. (Circ J 2007; 71: 897 - 903).