Despina Parcharidou

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.

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 β-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.

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

BackgroundThe 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.MethodsOur 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) ≥30 mm. The purpose of our study was the identification of high risk HCM patients coming from Northern Greece.ResultsFifteen patients (12.2%) of the whole cohort had MWT ≥ 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.ConclusionThis 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.

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

BackgroundHypertrophic 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 presentationWe 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.ConclusionThe 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.

Right Ventricular Dysfunction in Chronic Heart Failure

in Chronic Heart Failure The report by Rajagopalan et el1 demonstrated the beneficial effects of cardiac resynchronization therapy on right ventricular (RV) function independently of left ventricular (LV) ejection fraction improvement. An interesting point in the study is that patients with ischemic heart failure had a significantly lower baseline global composite of RV function Sm (the average velocity obtained at the tricuspid annulus and the basal and mid RV segments) compared with those in the nonischemic group. It is well confirmed that the presence of RV systolic dysfunction in patients with chronic heart failure is correlated with adverse hemodynamic and humoral response and survival.2 Whether the presence of RV dysfunction can be used as a tool to separate ischemic cardiomyopathy from idiopathic dilated cardiomyopathy is of clinical interest. Previous studies using gated equilibrium radionuclide angiography3 or high-frequency thermodilution and contrast ventriculography4,5 showed that idiopathic dilated cardiomyopathy is characterized by more severe RV systolic dysfunction than ischemic cardiomyopathy. The current implementation of tissue Doppler imaging echocardiographic technique results in conflicting conclusions. In a recent study,6 we studied 42 patients with ischemic cardiomyopathy and 40 patients with idiopathic dilated cardiomyopathy with conventional and tissue Doppler echocardiography. The 2 groups did not differ in terms of New York Heart Association class, LV ejection fraction, or pharmacologic treatment. Patients with ischemic cardiomyopathy had lower tricuspid annular motion systolic (RV Sa 0.06 vs 0.09 m/s, p 0.0001) and diastolic (RV Ea 0.05 vs 0.07 m/s, p 0.0003; RV Aa 0.075 vs 0.11 m/s, p 0.0016) velocities. They also exhibited a higher ratio of early transtricuspid filling velocity to early diastolic motion velocity of the tricuspid annulus (RV E/Ea 8.2 vs 5.7, p 0.0008). RV Sa, along with age and pulmonary artery systolic pressure, was an independent predictor of the diagnosis of ischemic cardiomyopathy. The discrepancy between our results and those of previous studies concerning RV impairment in chronic heart failure may be multifactorial. Previous studies included smaller cohorts,3 were retrospective, enrolled older patients with idiopathic dilated cardiomyopathy than those seen in clinical practice, or were designed in the pre-blocker era.4 Moreover, these studies had a low incidences of documented previous myocardial infarctions and prevalences of 3-vessel disease in patients with ischemic cardiomyopathy.4,5 A similar observation was reported by Plewka et al7 regarding the left ventricle, in which mitral Sm was lower, although not significantly, in ischemic than in idiopathic dilated cardiomyopathy, although the 2 groups had similar LV ejections fractions.7 Ventricular interdependence could contribute significantly to worse RV dysfunction in ischemic heart failure.8 In conclusion, we believe that RV dysfunction is more pronounced in ischemic than in idiopathic dilated cardiomyopathy. Tissue Doppler parameters are complementary to clinical and conventional echocardiographic findings and can facilitate the qualification for invasive procedures in patients with difficult-to-diagnose cardiomyopathy.

Determinants of functional mitral regurgitation severity in patients with ischemic cardiomyopathy versus nonischemic dilated cardiomyopathy.

Functional mitral regurgitation (MR) is prevalent among patients with left ventricular (LV) dysfunction and is associated with a poorer prognosis. Our aim was to assess the primary determinants of MR severity in patients with ischemic cardiomyopathy (ICM) and nonischemic dilated cardiomyopathy (DCM).

Normal systolic function in hypertrophic cardiomyopathy: reality or myth?

We would like to thank Efthimiadis et al. for their interest in our work. Indeed, it was long believed that patients with hypertrophic cardiomyopathy (HCM) had normal or supranormal systolic function despite mutations in genes encoding for sarcomeric proteins. This concept was, at least partly, based on the use of endocardial indices of systolic function such as ejection fraction. Ejection fraction is generally normal or supranormal in HCM patients. However, it is well known that ejection fraction is a …

Subaortic and midventricular obstructive hypertrophic cardiomyopathy with extreme segmental hypertrophy

BackgroundSubaortic and midventricular hypertrophic cardiomyopathy in a patient with extreme segmental hypertrophy exceeding the usual maximum wall thickness reported in the literature is a rare phenomenon.Case PresentationA 19-year-old man with recently diagnosed hypertrophic cardiomyopathy (HCM) was referred for sudden death risk assessment. The patient had mild exertional dyspnea (New York Heart Association functional class II), but without syncope or chest pain. There was no family history of HCM or sudden death. A two dimensional echocardiogram revealed an asymmetric type of LV hypertrophy; anterior ventricular septum = 49 mm; posterior ventricular septum = 20 mm; anterolateral free wall = 12 mm; and posterior free wall = 6 mm. The patient had 2 types of obstruction; a LV outflow obstruction due to systolic anterior motion of both mitral leaflets (Doppler-estimated 38 mm Hg gradient at rest); and a midventricular obstruction (Doppler-estimated 43 mm Hg gradient), but without apical aneurysm or dyskinesia. The patient had a normal blood pressure response on exercise test and no episodes of non-sustained ventricular tachycardia in 24-h ECG recording. Cardiac MRI showed a gross late enhancement at the hypertrophied septum. Based on the extreme degree of LV hypertrophy and the myocardial hyperenhancement, an implantation of a cardioverter-defibrillator was recommended prophylactically for primary prevention of sudden death.ConclusionMidventricular HCM is an infrequent phenotype, but may be associated with an apical aneurysm and progression to systolic dysfunction (end-stage HCM).

Triple type of obstruction in hypertrophic cardiomyopathy.

Case description A 19-year-old man with recently diagnosed hypertrophic cardiomyopathy (HCM) was referred to our department for sudden death risk assessment. The diagnosis was made by a private cardiologist to whom the patient was presented due to a history of cardiac murmur. The patient had mild exertional dyspnea (New York Heart Association functional class II), but without syncope or chest pain. There was no family history of HCM or sudden death. The patient’s blood pressure (BP) was 130/70 mmHg and a grade 3–4/6 systolic ejection murmur was present between the left parasternal border and the apex. The ECG showed a left ventricular (LV) hypertrophy with strain pattern. A two-dimensional echocardiogram revealed an asymmetrical type LV hypertrophy; anterior ventricular septum equal to 35 mm; posterior ventricular septum equal to 20 mm; anterolateral free wall equal to 12 mm; and posterior free wall equal to 6 mm (Fig. 1). The patient had three types of obstruction; LV outflow obstruction due to systolic anterior motion of both mitral leaflets with a Doppler-estimated 34 mmHg gradient at rest (Fig. 2a and b); a midventricular obstruction with a Doppler-estimated 55 mmHg gradient at rest but without apical aneurysm or dyskinesia (Fig. 2a and c); and right ventricular (RV) outflow tract obstruction with a Doppler-estimated 40 mmHg gradient at rest (Fig. 3). The LV end-diastolic dimension was 45 mm and the left atrium was 45 mm. The RV dimension was 30 mm and the RV free-wall thickness was 8 mm. No mitral or tricuspid regurgitation was detected. The patient had a normal BP response on exercise test with a VO2max of 20 ml/kg per minute and no episodes of nonsustained ventricular tachycardia in 24-h ECG recording. Cardiac magnetic resonance imaging (MRI) showed a gross late enhancement at the septum. On the basis of the extreme