Alessandra Rea

Prolonged left ventricular twist in cardiomyopathies: a potential link between systolic and diastolic dysfunction.

AIMS Left ventricular (LV) twist and untwist play a major role in LV mechanics. We sought to acquire new pathophysiological insights in cardiomyopathies (CM) studying LV twist dynamics by speckle tracking imaging (STI). METHODS AND RESULTS Standard echo-Doppler and STI study were performed in 67 CM patients divided in four age- and sex-matched subgroups: 18 with apical hypertrophic cardiomyopathy (Group A); 20 with asymmetrical hypertrophic cardiomyopathy (Group B); 15 with dilated cardiomyopathy (Group C); 14 with LV non-compaction (Group D). As controls, 34 age- and sex-matched normal subjects were studied. Compared with control group, all CM Groups showed significantly lower longitudinal, circumferential, and radial myocardial deformations (P < 0.05). LV twist was correlated with ejection fraction (EF; r = 0.62; P < 0.0001). Furthermore, all CM patients had a significantly lower twist rate (P < 0.05) and delayed onset of untwist (P < 0.01). Of interest a significant correlation was found between isovolumic relaxation time and untwist onset (r= 0.485, P < 0.0001). In addition, a significant correlation was found between longitudinal deformations and the onset of untwist (strain: r = 0.46, P = 0.0001; strain rate: r = 0.33, P = 0.0056) and between longitudinal strain rate and twisting rate (r= -0.38; P = 0.0015). CONCLUSION (i) All CM patients show an impairment of longitudinal, circumferential, and radial myocardial deformations; (ii) LV peak twist is impaired only in CM with reduced EF but preserved in those with normal or increased EF; (iii) LV twist is prolonged and untwisting onset is delayed in all CM, suggesting that a mechanical adaptation to subclinical systolic abnormalities might induce, by a prolonged LV twist, the early onset of diastolic dysfunction.

Abnormal regional myocardial deformation properties and increased aortic stiffness in normotensive patients with aortic coarctation despite successful correction: an ABPM, standard echocardiography and strain rate imaging study

The long-term follow-up data subsequent to a successful repair of AoC (aortic coarctation) show that life expectancy remains reduced. Previous standard echocardiographic studies have demonstrated normal or increased systolic cardiac function in patients following successful repair of AoC. SR (strain rate) imaging is a new technique able to detect subclinical myocardial abnormalities. In the present study we investigated whether young patients (without hypertension, as assessed using ambulatory blood pressure monitoring and an exercise test) following successful AoC repair already have abnormal myocardial deformation properties, and the relationship of the deformation properties with aortic stiffness. We studied 166 subjects, 83 AoC non-hypertensive patients (mean age 12+/-4 years) a number of years after successful repair of AoC and 83 age- and sex-matched subjects as controls. Peak systolic SR (1/s) for both regional longitudinal and radial function was assessed. The aortic stiffness index was calculated from the echocardiographically derived thoracic aortic diameters, and the measurement of blood pressure was obtained by cuff sphygmomanometry. The LV (left ventricular) ejection fraction was significantly increased in AoC patients, whereas regional longitudinal SRs were significantly reduced (-1.1+/-0.9 compared with -2+/-0.5, P<0.0001) in patients. The aortic stiffness index was significantly increased in AoC patients (12+/-9, P<0.0001). At multilinear regression analysis, age at repair (P=0.005; coefficient, -0.201; S.E.M., 0.027) and the aortic stiffness index (P=0.0029; coefficient, 0.334; S.E.M., 0.423) predicted longitudinal SR. Despite the presence of a successful repair for AoC, in the absence of hypertension, longitudinal deformation properties were significantly impaired. Moreover, the degree of longitudinal SR impairment was correlated with age at repair and aortic stiffness. Early repair can delay the onset of hypertension in postcoarctectomy patients, but cannot prevent the innate structural and functional abnormalities of the aorta and their deleterious effect on myocardial deformation properties.

Non Sustained Ventricular Tachycardia in Hypertrophic Cardiomyopathy and New Ultrasonic Derived Parameters

BACKGROUND The mechanism of sudden death in hypertrophic cardiomyopathy (HCM) is ventricular tachyarrhythmia emanating from myocyte disarray, fibrosis, and inhomogeneity in intramyocardial activation. Tissue synchronization imaging (TSI) allows the measurement of regional delay, while two-dimensional strain can be used to identify myocardial fibrosis. The aim of this study was to assess the relationship between new ultrasonically derived parameters and nonsustained ventricular tachycardia (NSVT) in patients with HCM. METHODS Ninety-three patients with HCM (mean age, 36 +/- 16 years) and 30 patients with hypertension with secondary left ventricular (LV) hypertrophy (mean age, 42 +/- 10 years; 65% men) were studied. All underwent standard echocardiographic, TSI, and two-dimensional strain examinations. Patients were followed every 3 months for 2 years. Holter monitoring was performed every 3 months. The primary endpoint was the occurrence of NSVT. RESULTS Twenty-four patients (26%) had >or=1 episode of NSVT. Patients with NSVT had a higher value of maximal LV thickness (22 +/- 6 vs 19 +/- 5 mm, P = .04). There were no significant associations between NSVT on Holter monitoring and LV outflow gradient, New York Heart Association class, syncope, and medical therapy. N-terminal pro-brain natriuretic peptide values were significantly (P = .01) higher in patients with NSTV (1034 +/- 1088 vs 561 +/- 593 pg/mL). Patients with HCM and NSVT had (1) similar values on TSI-studied parameters to patients without NSVT, (2) significant reductions in basal and mid septal strain and in basal anterior-septal strain, and (3) more frequently peak systolic strain >or= -10% (P < .0001). In multivariate analysis, the presence of >3 LV segments with longitudinal two-dimensional strain >or= -10% (sensitivity, 81%; specificity, 97.1%; area under the curve, 0.944; P < .0001) was an independent predictor of NSVT. CONCLUSIONS Using a simple, inexpensive, easily available, and bedside-usable tool, it was possible to recognize with good sensitivity and specificity patients with HCM at higher risk for NSVT.

Transverse strain predicts exercise capacity in systemic right ventricle patients.

BACKGROUND Because transposition of great arteries (TGA) patients who underwent atrial switch repair (AS) remain asymptomatic for decades before development of symptomatic heart failure, there may be some clinical value to preclinical detection of ventricular dysfunction. Detection of systemic right ventricular (RV) dysfunction in patients who are asymptomatic may prompt early initiation of heart failure therapy and more frequent clinical follow-up. AIM The objective of this study was to characterize longitudinal and transverse systolic function of the systemic RV using two-dimensional (2D) strain in patients with TGA after AS repair and to correlate these parameters with their exercise capacity. METHODS The study population consisted of 26 patients (20±6 years) with TGA after AS operation. Conventional echocardiography and bidimensional strain were performed on consecutive patients reporting to the out patient congenital heart disease clinic. Twenty-four healthy, age-matched individuals were used as control subjects. Analysis was performed on the non-systemic RVs of the control group. All the studied patients underwent treadmill exercise testing according to the Bruce II protocol. RESULTS RV longitudinal 2D-strain in controls showed a base to apex gradient, while in patients was homogeneously reduced. Also RV transverse strain (i.e the radial deformation assessed by the apical 4 chamber view) showed a base to apex gradient in controls, while in patients was significantly increased in the mid and apical segments. In the systemic RV free wall, transverse strain was greater than longitudinal strain (p<0.0001), opposite from findings in the normal RV free wall (p: NS). Of interest, in AS-TGA patients we found a strong correlation between RV transverse 2D strain and exercise capacity (p<0.0001; R: 0.80). At multivariate analysis (including age, degree of tricuspid regurgitation, TAPSE, RV area fractional change, RV visually estimated ejection fraction, RV global longitudinal strain and RV global transverse strain) the best predictor of exercise capacity in AS-TGA patients was transverse 2D strain (p<0.0001). CONCLUSIONS In AS-TGA patients there is a shift from a predominant longitudinal shortening to a predominant transverse thickening. The transverse thickening assessed by 2D transverse strain is correlated to exercise capacity of these patients. In the follow up of AS-TGA patients the monitoring of RV transverse myocardial deformation properties should be considered more than the simple evaluation of RV longitudinal function.

Usefulness of Bidimensional Strain Imaging for Predicting Outcome in Asymptomatic Patients Aged < 16 Years With Isolated Moderate to Severe Aortic Regurgitation

Aortic regurgitation (AR) has increased in the pediatric population because of the expanded use of new surgical and hemodynamic procedures. Unfortunately, the exact timing for operation in patients with AR is still debated. Conventional echocardiographic parameters, left ventricular (LV) dimensions and the LV ejection fraction, have limitations in predicting early LV dysfunction. Two-dimensional strain imaging, an emerging ultrasound technology, has the potential to better study those patients. The aim of this study was to assess the prognostic value of 2-dimensional longitudinal strain in young patients with congenital isolated moderate to severe AR. Twenty-six young patients with asymptomatic AR (aged 3 to 16 years) were studied. The mean follow-up duration was 2.9 ± 1.2 years (range 0.5 to 6). Baseline LV function by speckle-tracking and conventional echocardiography in patients with stable disease was compared with that in patients with progressive AR (defined as development of symptoms, increase in LV volume ≥15%, or decrease in the LV ejection fraction ≤10% during follow-up). LV ejection fractions were similar between groups. The jet area/LV outflow tract area ratio was significantly increased in patients with AR with progressive disease (31.2 ± 5.6% vs 39.2 ± 3.8%, p <0.001). The peak transmitral early velocity/early diastolic mitral annular velocity ratio was significantly increased in patients with progressive AR (p = 0.001). LV average longitudinal strain was significantly reduced in patients with progressive AR compared to those with stable AR (-17.8 ± 3.9% vs -22.7 ± 2.7%, p = 0.001). On multivariate analysis, the only significant risk factor for progressive AR was average LV longitudinal strain (p = 0.04, cut-off value >-19.5%, sensitivity 77.8%, specificity 94.1%, area under the curve 0.889). In conclusion, 2-dimensional strain imaging can discriminate young asymptomatic patients with progressive AR. This could allow young patients with AR to have a better definition of surgical timing before the occurrence of irreversible myocardial damage.

Assessment of left-ventricular mass and remodeling in obese adolescents: M-mode, 2D or 3D echocardiography?

Background Although there have been several studies about the impact of obesity on left-ventricular mass (LVM) and remodeling and their influence on cardiovascular morbidity and mortality, no studies are available on the best echocardiographic technique to study them. In addition, the role of systemic hypertension on LVM in obese adolescents has not been adequately investigated. Aims To compare LVM and remodeling pattern assessed by M-mode, two-dimensional (2D) and three-dimensional (3D) echocardiography in obese adolescents, and to correlate LVM with 24-h ambulatory blood pressure measurements. Methods We studied 120 adolescents: 86 obese patients by M-mode, 2D and 3D echocardiography and 34 normal individuals by echo and magnetic resonance imaging (MRI). Results In normal individuals LVM was assessed by 3D echo and had the strongest correlation to MRI. In obese adolescents left-ventricular geometry was abnormal in 27 patients (31%) by 3D echo, in 21 patients (24%) by 2D echo and in 43 patients (50%) by M-mode. Mean SBP was significantly related to relative wall thickness, body mass index (BMI) and LVM/h2.7 evaluated by 3D echo [r = 0.52 (P < 0.0001), r = 0.36 (P = 0.004) and r = 0.28 (P = 0.03), respectively]. However, at a multivariate analysis, BMI showed a stronger correlation with LVM/h2.7 assessed by 3D compared to mean SBP (r = 0.44 and P = 0.001 vs. r = 0.26, P = 0.1). Conclusions In young patients LVM assessed by 3D echo had the strongest correlation to MRI compared to 2D and M-mode echo. In obese adolescents, 3D echo showed left-ventricular remodeling in 31% with LVM more significantly correlated with BMI compared to mean SBP.

Heart rate variability is a weak predictor of sudden death in children and young patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) carries a relatively high risk of sudden death, particularly in young people.1,2 To date, the clinical significance of heart rate variability (HRV) in patients with HCM is still controversial.3,4 Our study aimed to analyse HRV in a relatively large cohort of children and young patients with HCM, and to assess potential correlations with clinical markers of sudden death. In all, 53 patients diagnosed with HCM between the ages of 18 and 40 years and body surface area-matched controls were included in this study. The diagnosis of HCM was based on echocardiographic evidence of increased wall thickness, 2 standard deviations (SD) or more compared with age, sex and body surface area-matched people. Maximal ventricular wall thickness (MWT) was defined as the greatest thickness in any segment and measured as the absolute value and as Z score. At the time of the study, age of patients ranged from 1 to 220 months (mean 75.6 (SD 73.7)). Patients with HCM underwent physical examination, rest electrocardiography, conventional echocardiography, exercise test and 24-h …

Right Ventricular Cardiomyopathies: A Multidisciplinary Approach to Diagnosis

The physiological importance of the right ventricle (RV) has been underestimated over the past years. Finally in the early 1950s through the 1970s, cardiac surgeons recognized the importance of RV function. Since then, the importance of RV function has been recognized in many acquired cardiac heart disease. RV can be mainly or together with left ventricle (LV) affected by inherited or acquired cardiomyopathy. In fact, RV morphological and functional remodeling occurs more common during cardiomyopathies than in ischemic cardiomyopathies and more closely parallels LV dysfunction.

Natriuretic peptides: molecular biology, pathophysiology and clinical implications for the cardiologist

Natriuretic peptides (NPs) counter the effects of volume overload or adrenergic activation of the cardiovascular system. They are able to induce arterial vasodilatations, natriuresis and diuresis, and they reduce the activities of the renin-angiotensin-aldosterone system and the sympathetic nervous system. However, in addition to wall stress, other factors have been associated with elevated natriuretic peptide levels. Since 2000, because of their characteristics, NPs have become quantitative plasma biomarkers of heart failure. Nowadays, NPs play an important role not only in the diagnosis of heart failure, but also for a prognostic purpose and a guide to medical therapy. Finally, a new drug that modulates the NP system or recombinant analogs of NPs are now available in patients with heart failure.

Right ventricular hypertrabeculation associated with double-outlet left ventricle: exaggeration of a normal pattern or right ventricular cardiomyopathy?

We describe a rare case of double-outlet left ventricle, ventricular septal defect, and subpulmonary valve stenosis surgically corrected by Rastelli procedure, developing severe homograft obstruction with right ventricular dilation and extensive hypertrabeculation/noncompaction during follow-up. We briefly discuss the cause diagnosis, and clinical significance of right ventricular hypertrabeculation/noncompaction.