QRS analysis using wavelet transformation for the prediction of response to cardiac resynchronization therapy: a prospective pilot study.

BACKGROUND: Wider QRS and left bundle branch block morphology are related to response to cardiac resynchronization therapy (CRT). A novel time-frequency analysis of the QRS complex may provide additional information in predicting response to CRT. METHODS: Signal-averaged electrocardiograms were prospectively recorded, before CRT, in orthogonal leads and QRS decomposition in three frequency bands was performed using the Morlet wavelet transformation. RESULTS: Thirty eight patients (age 65±10years, 31 males) were studied. CRT responders (n=28) had wider baseline QRS compared to non-responders and lower QRS energies in all frequency bands. The combination of QRS duration and mean energy in the high frequency band had the best predicting ability (AUC 0.833, 95%CI 0.705-0.962, p=0.002) followed by the maximum energy in the high frequency band (AUC 0.811, 95%CI 0.663-0.960, p=0.004). CONCLUSIONS: Wavelet transformation of the QRS complex is useful in predicting response to CRT.

Clinical characteristics and natural history of hypertrophic cardiomyopathy with midventricular obstruction.

BACKGROUND: The prevalence, clinical characteristics and natural history of patients with hypertrophic cardiomyopathy (HCM) and midventricular obstruction (MVO) have not been adequately studied. METHODS AND RESULTS: A single-center cohort consisting of 423 patients (mean age, 49.3±17.2 years; 66.2% male) was thoroughly followed up for a median of 84 months (7 years; range, 6-480 months). MVO, characterized by the echocardiographic appearance of midventricular muscular apposition with a simultaneous mid-cavitary gradient ≥30mmHg, was identified in 34 patients (8%). Patients with MVO tended to be more symptomatic during their initial evaluation (>90% presented with NYHA class ≥II) compared to the rest of the HCM cohort. Apical aneurysm formation was identified in more than one-fourth of patients with MVO (26.5%), being a characteristic of the group. On multivariate Cox regression hazard analysis, presence of MVO strongly predicted progression to end-stage (burnt out) HCM and related heart failure (HF) deaths (hazard ratio, [HR], 2.62; 95% confidence interval [CI]: 1.2-8.8; P=0.047), as well as sudden death and associated lethal arrhythmic events (HR, 3.3; 95% CI: 1.26-8.85; P=0.016). CONCLUSIONS: MVO is a distinct phenotype of HCM associated with unfavorable prognosis in terms of end-stage HCM, sudden death and lethal arrhythmic events. The high adverse outcome rate necessitates early recognition of MVO and appropriate therapeutic interventions.

A de novo novel cardiac ryanodine mutation (Ser4155Tyr) associated with catecholaminergic polymorphic ventricular tachycardia.

We describe the case of a 14-year-old girl with a history of syncopal episodes triggered by stress or exercise. Catecholaminergic polymorphic ventricular tachycardia was diagnosed with the aid of an implantable loop recorder. The genetic testing of the patient and her family revealed a de novo novel missense mutation (Ser4155Tyr) in the exon 90 of the ryanodine receptor gene. This mutation affects a highly conserved residue (S4155) and results to replacement of serine (S) with tyrosine (Y) leading to change in physical and chemical properties. The girl was treated with an implantable defibrillator, metoprolol and flecainide. Over 1 year of follow-up she had no recurrence of ventricular tachycardia.

Quinidine: an "endangered species" drug appropriate for management of electrical storm in brugada syndrome.

Brugada syndrome is an inherited channelopathy associated with an increased risk of syncope and sudden cardiac death. In rare cases it can be manifested with electrical storm. We report two cases of Brugada syndrome that presented with electrical storm and were treated successfully with oral quinidine, an "endangered species" drug.

Somatostatin analogue scintigraphy in a patient with viral myocarditis.

Myocarditis may present clinically with a wide range of manifestations and often remains unrecognized. The diagnosis of myocarditis traditionally has been based on histological findings, but endomyocardial biopsy has a low sensitivity and clinicians are reluctant to proceed with an invasive diagnostic technique. Among newer diagnostic approaches, cardiac magnetic resonance imaging has gained acceptance as an efficient noninvasive tool to determine myocardial inflammation. In this context, imaging with radiolabeled somatostatin analogues could also be relevant because of their ability to delineate inflammatory sites. In conclusion, a case is presented in which somatostatin receptor imaging of the myocardium with (99m)Tc-depreotide tomography was used in the assessment of viral myocarditis.

Prognostic value of right ventricular diastolic function indices in hypertrophic cardiomyopathy.

AIMS: Despite the fact that the role of left ventricular diastolic dysfunction in hypertrophic cardiomyopathy (HCM) patients' prognosis has been established, the effect of increased right ventricular (RV) diastolic filling pressures still remains unclear. The purpose of this study was to determine the prognostic significance of transthoracic echocardiographic indices of RV diastolic function (tricuspid inflow and tricuspid annulus tissue Doppler imaging) in HCM patients. METHODS AND RESULTS: We followed up 386 patients diagnosed with HCM (aged 49.3 ± 17.2 years; 65% male) for a median period of 67 months (interquartile range 26-189 months). Primary endpoints were considered mortality due to heart failure (HF) (13 patients) and total cardiovascular (TC) mortality [HF, sudden cardiac death and its equivalents (35 patients)]. Patients presenting with an increased RV E/E(r) ratio (ratio of tricuspid in flow E wave to E(r) wave obtained by tissue Doppler imaging at the lateral tricuspid annulus) had a 1.6 times greater risk for HF mortality [hazard ratio (HR): 1.6, 95% confidence interval (CI): 1.1-2.4, P = 0.03] while patients with shortened tricuspid E wave deceleration time (DTE) had a 1.1 greater risk for SCD (HR: 1.1, 95% CI: 1.01-1.2, P = 0.03). Following ROC analysis, the optimal RV indices' cut-off values for the recognition of our study endpoints were assessed [E/E(r) = 6.88, sensitivity 75%, specificity 77.4%, area under curve (AUC) 0.847, P = 0.017 for HF mortality and DTE < 239 ms, sensitivity 62.5%, specificity 56.7%, AUC 0.642, P = 0.05 for TC mortality]. CONCLUSION: The establishment of RV restrictive physiology appears to have significant predictive value in HCM, regardless of the presence of other detrimental risk factors.

Worsening heart failure as the main manifestation of neglected complete extrusion of a cardiac resynchronization therapy pacemaker.

A patient with dilated cardiomyopathy presented at the emergency department with a completely extruded cardiac resynchronization therapy pacemaker, complaining of worsening dyspnea. The device was functioning intermittently, and no evidence of local or systemic inflammation was observed. The patient had been living with the device hanging against his chest for several weeks and he eventually sought medical assistance because of worsening heart failure. The device and leads were extracted, but the patient refused a new implantation at the contralateral site.

The use of transtelephonic loop recorders for the assessment of symptoms and arrhythmia recurrence after radiofrequency catheter ablation.

Radiofrequency catheter ablation (RFA) is an effective treatment of arrhythmias. However, patients often remain symptomatic after the procedure. We aimed to assess the arrhythmia recurrence after successful RFA in relation to patients' symptoms using transtelephonic loop recorders. Thirty-six consecutive patients (age 50 +/- 14 years, 17 males/19 females) were enrolled after successful RFA for atrioventricular (AV) nodal reentrant tachycardia (n = 21), AV reentrant tachycardia (n = 8), atrial tachycardia (n = 2), atrial fibrillation/flutter (n = 4), and ventricular tachycardia (n = 1). During 23 +/- 6 days of follow-up, 679 events were recorded, 246 of which were true arrhythmic events, mostly (56%) asymptomatic. The vast majority of these true arrhythmic events were due to trivial arrhythmias (extrasystoles or sinus tachycardia), equally distributed among symptomatic and asymptomatic episodes. Arrhythmia relapse was shown in four patients, who had a total of nine episodes, eight of which were symptomatic. No high degree AV block was detected. Overall, symptom recurrence had low sensitivity (44%) and high specificity (95%) for the detection of any arrhythmia, and high sensitivity (89%) but low specificity (58%) for the detection of relapse. In conclusion, transtelephonic monitoring was a useful tool for the assessment of symptoms after RFA and its use may be reserved for the most symptomatic patients to detect a relapse or to reassure them for the benign nature of their symptoms.

Hypertrophic cardiomyopathy with midventricular obstruction and apical aneurysm formation in a single family: case report.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is an extremely heterogeneous disease. An under recognized and very often missed subgroup within this broad spectrum concerns patients with left ventricular (LV) apical aneurysms in the absence of coronary artery disease. CASE PRESENTATION: We describe a case of HCM with midventricular obstruction and apical aneurysm formation in 3 patients coming from a single family. This HCM pattern was detected by 2D-echocardiography and confirmed by cardiac magnetic resonance imaging. A cardioverter defibrillator was implanted in one of the patients because of non-sustained ventricular tachycardia detected in 24-h Holter monitoring and an abrupt drop in systolic blood pressure during maximal exercise test. The defibrillator activated 8 months after implantation by suppression of a ventricular tachycardia providing anti-tachycardia pacing. The patient died due to refractory heart failure 2 years after initial evaluation. The rest of the patients are stable after a 2.5-y follow-up period. CONCLUSION: The detection of apical aneurysm by echocardiography in HCM patients may be complicated. Ventricular tachycardia arising from the scarred aneurysm wall may often occur predisposing to sudden death.

Identification of high risk patients with hypertrophic cardiomyopathy in a northern Greek population.

BACKGROUND: The percentage of hypertrophic cardiomyopathy (HCM) patients who are in high risk for Sudden Death (SD) constitutes only a minority of all HCM population but the incidence of SD in this subset is high (at least 5% annually). The identification of this small but important proportion of high risk HCM patients has been the clue in the clinical evaluation of these patients. METHODS: Our study cohort consisted from 123 patients with HCM who are currently followed up in our Institution. Five clinical risk factors were assessed: a family history of premature SD, unexplained syncope, Non Sustained Ventricular Tachycardia (NSVT) on 24-h ECG monitoring, Abnormal Blood Pressure Response (ABPR) during upright exercise testing and Maximum left ventricular Wall Thickness (MWT) > or =30 mm. The purpose of our study was the identification of high risk HCM patients coming from Northern Greece. RESULTS: Fifteen patients (12.2%) of the whole cohort had MWT > or = 30 mm, 30 patients (24.4%) had an ABPR to exercise, 17 patients (13.8%) had episodes of NSVT in 24-h Holter monitoring, 17 patients (13.8%) suffered from syncope, and 8 patients (6.5%) had a positive family history of premature SD. Data analysis revealed that 74 patients (60.1%) had none risk factor. Twenty four patients (19.5%) had 1 risk factor, 17 patients (13.8%) had 2 risk factors, 4 patients (3.25%) had 3 risk factors, and 4 patients (3.25%) had 4 risk factors, while none patient had 5 risk factors. Twenty five patients (20.3%) had 2 or more risk factors. CONCLUSION: This study for the first time confirms that, although a 60% of patients with HCM coming from a regional Greek population are in low risk for SD, a substantial proportion (almost 20%) carries a high risk for SD justifying prophylactic therapy with amiodaron or ICD implantation.

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.

Prevalence of systolic impairment in an unselected regional population with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HC) may transition to a phase characterized by systolic impairment resembling dilated cardiomyopathy. This study retrospectively assessed the incidence of left ventricular (LV) systolic impairment at initial clinical evaluation in 248 consecutive patients with HC (mean age 53 +/- 16 years). HC with systolic impairment was diagnosed if the LV ejection fraction was <50%, calculated by echocardiography. Twenty patients (8%) had HC with LV systolic impairment at initial evaluation. Patients with systolic impairment had a greater incidence of family histories of sudden cardiac death (SCD) than patients with preserved systolic function (25% vs 5.3%, p = 0.006) and more severe functional limitations (New York Heart Association class >or=III, p <0.001). All-cause mortality and cardiovascular mortality did not differ between the 2 groups. The incidence of SCD was 1.7% in patients with normal LV ejection fractions, and no SCD was observed in patients with systolic impairment. The latter group had more frequent major cardiac events (SCD, ventricular fibrillation, aborted cardiac arrest, and first implantable cardioverter-defibrillator discharge; p = 0.03). During follow-up, 2 patients progressed to HC with systolic impairment (annual incidence 0.85%). In conclusion, systolic impairment is not exceptional in patients with HC at initial evaluation and is associated with functional deterioration and major cardiac events.

Similar pattern of diastolic function adaptation of both ventricles to programmed atrioventricular interval modification in patients with DDD pacing.

OBJECTIVE: To evaluate both left ventricular (LV) and right ventricular (RV) diastolic performance adaptation to variable atrioventricular interval (AVI), in patients with DDD pacing for complete heart block and to investigate a possible interaction between LV and RV in this specific cohort of patients. METHODS: We studied 22 consecutive patients (mean age 65.2 +/- 14.3 years) who underwent DDD pacemaker implantation following admission for complete heart block. One day following implantation, patients were paced at 3 different pacing modes, under the same programmed heart rate and a different AVI (100, 150 and 200 ms respectively). Standard Doppler echocardiography of mitral and tricuspid valve inflow was performed to evaluate LV and RV diastolic function, during each pacing mode. RESULTS: Left ventricular and RV diastolic performance adaptation to variable AVI modifications was similar, showing a progressive increase of late diastolic filling velocities and a subsequent decrease of E/A wave ratios following AVI prolongation. A short AVI of 100 or 150 ms was associated with improved LV and RV diastolic filling dynamics. CONCLUSIONS: In elderly patients with complete heart block and unimpaired systolic function undergoing DDD pacemaker implantation, both ventricles share a similar pattern of diastolic function adaptation to AVI modifications and that might be the reflection of ventricular interaction under this specific pacing mode.

Left ventricular Doppler characteristics in first-degree relatives of patients with hypertrophic cardiomyopathy.

Left ventricular (LV) diastolic function may be affected early in patients with hypertrophic cardiomyopathy (HCM), regardless of the phenotypic expression of the disease. The aim of the present study was to detect whether LV diastolic performance, evaluated by conventional Doppler echocardiography, is impaired in first-degree relatives of patients with phenotypically expressed HCM, who had no clinical, electrocardiographic, or echocardiographic signs of the disease. Twenty-two young adults having the previously described characteristics comprised the study population and 22 sex- and age-matched healthy individuals served as controls. The 2 groups were compared according to several echocardiographic parameters and the following diastolic function indices: peak velocity of E wave, representing early filling; peak velocity of A wave, representing late filling; ratio of peak early to peak late velocity (E/A); deceleration time of E wave; and LV isovolumic relaxation time. Slower deceleration time of transmitral early filling in first-degree relatives of patients with HCM (192 +/- 31 vs 149 +/- 31 msec, p < 0.001) was the only variable that significantly differentiated the 2 groups. This study shows that in healthy persons with a family history of HCM, Doppler-derived mitral filling pattern shifted toward that observed in HCM and the slower deceleration time may serve as an early sign of disease development.

Right ventricular diastolic function in patients with chronic aortic regurgitation.

Right ventricular diastolic function was evaluated using Doppler echocardiography in 40 patients with aortic regurgitation. Abnormal right ventricular relaxation and filling were the main findings of our study.

Doppler echocardiographic evaluation of right ventricular diastolic function in patients with mitral regurgitation.

BACKGROUND AND AIM OF THE STUDY: The effect of left ventricular (LV) pressure overload on right ventricular (RV) diastolic function has been extensively studied. In contrast, no data are available concerning the influence of LV volume overload on RV diastolic function. Accordingly, RV diastolic function was studied in patients with mitral regurgitation (MR) using Doppler echocardiography. METHODS: RV diastolic indices were calculated, using pulsed Doppler echocardiography, in 30 patients (mean age 56.87 +/- 8.58 years) with severe MR, and in 30 healthy control subjects (mean age 56.67 +/- 8.52 years). RESULTS: Compared with controls, MR patients had a significantly lower RV E/A ratio (0.85 +/- 0.12 versus 1.21 +/- 0.16, p <0.001), a significantly prolonged RV isovolumic relaxation time (70 +/- 20 versus 30 +/- 10 ms, p <0.001), a significantly prolonged deceleration time of the transtricuspid E wave (210 +/- 20 versus 140 +/- 10 ms, p <0.001), and a significantly greater right atrial filling fraction (38.58 +/- 4.59 versus 32.58 +/- 3.14%, p <0.001). There was no statistically significant correlation between RV diastolic indices and LV mass index and interventricular septum thickness. CONCLUSION: RV diastolic function in patients with MR is impaired, reflecting prolonged relaxation and redistribution of RV filling into late diastole. Ventricular interdependence constitutes the most likely mechanism of this action.

Surgical septal myectomy for hypertrophic cardiomyopathy in Greece: a single-center initial experience.

INTRODUCTION: Surgical septal myectomy is thought to be the gold standard of treatment for obstructive hypertrophic cardiomyopathy (HCM) with obstruction symptoms refractory to optimal medical therapy. In Europe, during the last 2 decades, myectomy has been set aside, while alcohol septal ablation has been widely promoted. In this paper, we analyze our first experience of surgical septal myectomy in a small cohort of patients with HCM coming from a single tertiary center. METHODS: Thirty-two patients (16 male, 50%) with a mean age of 58.1 ± 14.4 (range 12-79 years) underwent myectomy for HCM symptoms refractory to negative inotropic agents. The technique used for the myectomy was the one introduced by Andrew Morrow. Mean follow-up time after procedure was 16.8 ± 13.3 months with a median of 13 months (range 4-58 months). RESULTS: Post-myectomy, there was a significant improvement in patients' NYHA class (from 3.3 ± 0.46 to 1.38 ± 0.49, p<0.0005), while interventricular septum thickness was reduced from 2.3 ± 0.4 cm to 1.6 ± 0.4 cm (p<0.0005), and peak gradient at the site of obstruction from 94.9 ± 29 to 16.7 ± 7.9 mmHg (p<0.0005). During the follow-up period, only 1 out of 32 patients died, from non-cardiovascular causes, with the overall survival post-myectomy being 97.2% (95%CI: 94.5-99.9%) at 1-year follow up. CONCLUSIONS: Surgical septal myectomy in patients with HCM and drug-refractory symptoms is a safe procedure that greatly improves symptoms and quality of life. Further follow-up of our patients is mandatory in order to determine whether the good survival rate achieved at 1 year will persist.

Increased right atrial volume index predicts low Duke activity status index in patients with chronic heart failure.

INTRODUCTION: The aim of the present study was to examine the value of the right atrial volume index (RAVI) as predictor of functional capacity in patients with heart failure. METHODS: A total of 51 patients with stable chronic heart failure of ischaemic or non-ischaemic aetiology were prospectively enrolled. The systolic function of the right ventricle was quantified using the tricuspid annular plane systolic excursion (TAPSE). Right atrial volume was measured in the apical 4-chamber view and was indexed to body surface area. The functional capacity was assessed by the Duke Activity Status Index (DASI). RESULTS: Patients with a low functional capacity (DASI<10) had lower TAPSE (1.4 ± 0.3 cm versus 2.0 ± 0.4 cm, p<0.001), higher RAVI (42 ± 15 ml/m(2) versus 22 ± 9 ml/m(2), p<0.001), higher estimated right ventricular systolic pressure (61 ± 13 mmHg versus 40 ± 16 mmHg, p<0.001), larger right ventricular end-diastolic diameter (4.7 ± 0.8 cm versus 3.6 ± 0.7 cm, p<0.001) and lower left ventricular ejection fraction (26 ± 6% versus 30 ± 7%, p=0.022). Multivariate analysis revealed that TAPSE was the single independent predictor of DASI. In the subgroup of patients with reduced right ventricular systolic function (TAPSE<2 cm), RAVI was the single independent predictor of low DASI. In the overall population RAVI=30.6 ml/m(2) had 75% sensitivity and 83% specificity in predicting DASI<10. Within the subgroup of patients with TAPSE<2 cm, RAVI=30.6 ml/m(2) had better sensitivity and specificity (79% and 90% respectively) in predicting DASI<10. CONCLUSIONS: Increased right atrial volume index predicts low functional capacity quantified by the Duke Activity Status Index in patients with stable chronic heart failure.