Ventricular Motion Research Articles

The mechanisms, diagnosis and management of mitral regurgitation in mitral valve prolapse and hypertrophic cardiomyopathy.

Valvular disease is a frequent cardiac pathology leading to heart failure and, ultimately, death. Mitral regurgitation, defined as the inability of the two mitral leaflets to coapt, is a common valvular disease and a self sustained pathology. A better understanding of the mitral valve histological layers provides a better understanding of the leaflet and chordae changes in mitral valve prolapse. Mitral valve prolapse may occur in myxomatous degenerative abnormalities, connective tissue disorders or in sporadic isolated cases. It is the most common mitral abnormality of non-ischemic cause leading to severe surgery-requiring mitral regurgitation. In addition to standard echocardiographic investigations, newly implemented three-dimensional techniques are being used and they permit a better visualisation, from the so-called ‘surgical view’, and an improved evaluation of the mitral valve. Hypertrophic cardiomyopathy is the most frequent inherited myocardial disease caused by mutations in various genes encoding proteins of the cardiac sarcomere, leading to a marked left ventricular hypertrophy unexplained by other comorbidities. The pathological echocardiographic hallmarks of hypertrophic cardiomyopathy are left ventricular hypertrophy, left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve. The systolic anterior motion of the mitral valve contributes to the development of mitral regurgitation and further narrows the left ventricular outflow tract, leading to more severe symptomatology. Cardiac magnetic resonance imaging accurately measures the left ventricular mass, the degree of diastolic function and it may also be used to distinguish phenotypic variants. The clinical outcome of patients with these pathologies is mostly determined by the selected option of treatment. The purpose of surgical correction regarding mitral valve involvement is to restore valvular competence. Surgery has proven to be the only useful treatment in preventing heart failure, improving symptomatology and reducing mortality. Our approach wishes to enhance the understanding of the mitral valve’s involvement in hypertrophic cardiomyopathy and mitral valve prolapse from genetic, haemodynamic and clinical perspectives, as well as to present novelties in the grand field of treatment.

96-67: Left Ventricular Motion and Strain Profiles in Patients with Normal and Impaired Systolic Function: Evaluating a Sensor-Based, Non-Fluoroscopic Tracking Technology

96-67: Left Ventricular Motion and Strain Profiles in Patients with Normal and Impaired Systolic Function: Evaluating a Sensor-Based, Non-Fluoroscopic Tracking Technology

Spontaneous coronary artery dissection in the presence of myocardial bridge causing myocardial infarction: an insight into mechanism

Article history: Received 18 December 2015 Accepted 3 January 2016 Available online 7 January 2016 or alcohol abuse as well as history of smoking. Troponin level was normal. Echocardiography showed ejection fraction of 61% with focal ventricular motion abnormality. Coronary angiography was performed. Severe compromise of blood flow in the left anterior descending artery was present. Subsequent optical coherence tomography examination revealed extensive coronary dissection of left anterior descending artery

Clinical effects of combined treatment by optimal dose of furosemide and spironolactone on diastolic heart failure in elderly patients.

Diastolic heart failure (DHF) is characterized by symptoms including reduced ventricular relaxation and compliance, resulting in congestion of pulmonary and systemic circulation. The curative effects of regular cardiac agents are ineffective. Thus, new agents are required to treat chronic cardiac failure. The aim of the present study was to examine the clinical effects of the combined treatment by optimal dose of furosemide (20 mg/day) and spironolactone (40 mg/day) on elderly patients with diastolic heart failure (DHF) [New York Heart Association (NYHA) 1–2 grade]. A total of 93 patients diagnosed with DHF between February, 2013 and February, 2014 were enrolled in the present study. The patients were randomly divided into the furosemide group (20 mg/day, n=27), optimal dose group (20 mg/day furosemide+40 mg/day spirolactone, n=36), and large dose group (40 mg/day furosemide+100 mg/day spirolactone, n=30). Following treatment for one month, a comparison and analysis of the NYHA class, left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDD), left ventricular wall segmental motion among the three groups were performed. The re-hospitalization rate of heart failure and incidence of electrolyte disorder among the three groups was compared and their differences analysed. Compared with pretreatment, the NYHA classifications of the three groups after treatment were reduced and differences were statistically significant (P<0.05). By contrast, for the NYHA classification after treatment there was no statistical significance (P>0.05). Compared with pretreatment, LVEF of the optimal dose group increased, LVEDD decreased, and the average systolic myocardial peak velocity and early diastolic myocardial peak velocity of ventricular wall motion were reduced, with differences being statistically significant (P<0.05). By contrast, in the furosemide and large dose groups no statistical significance was identified before and after the treatment (P>0.05). Improvement of the optimal dose group following treatment was more significant than the remaining two groups, and differences were statistically significant (P<0.05). The re-hospitalization rate of heart failure and incidence of electrolyte disorder in the optimal dose group following treatment were significantly less than the other two groups, and differences were statistically significant (P<0.05). In conclusion, the optimal dose (20 mg/day furosemide+40 mg/day spirolactone) significantly improved the clinical symptoms of elderly DHF patients (NYHA 1–2 grade) and ameliorated their long-term prognosis.

Myocardial dysfunction in patients with aortic stenosis and hypertensive heart disease assessed by MR tissue phase mapping.

To identify abnormalities of myocardial velocities in patients with left ventricular pressure overload using magnetic resonance tissue phase mapping (TPM). Thirty-three patients (nine with hypertensive heart disease [HYP], 24 with aortic stenosis [AS]) and 41 healthy controls were enrolled. To assess left ventricular motion, a basal, midventricular, and apical slice were acquired using three-directional velocity-encoded phase-contrast MR with a 3T system. Target parameters were peak longitudinal (Vz ) and radial (Vr ) velocity in systole and diastole (Peaksys , Peakdias ). Analysis was done on each myocardial segment. In a subgroup (n = 7 HYP, n = 12 AS, n = 24 controls), measurement was repeated during handgrip exercise. AS had significantly lower Vz -Peaksys in the inferolateral and inferoseptal wall (P = 0.003-0.029) and Vr -Peaksys in the septum and anterior wall (P = 0.001-0.013) than controls. Vz -Peakdias and Vr -Peakdias were lower in AS than in controls in almost all segments (P < 0.001-0.028). HYP showed reduced Vz -Peakdias compared to controls in all basal segments as well as in the lateral midventricular wall (P < 0.001-0.045), and reduced Vr -Peakdias compared to controls predominantly in the midventricular and apical segments (P = 0.004-0.042). AS patients with focal fibrosis had significantly reduced myocardial velocities (P = 0.001-0.047) in segments without late enhancement. During exercise, Vz -Peaksys , Vr -Peaksys , and Vz -Peakdias remained unchanged in AS and HYP, but decreased in the lateral wall in controls (P < 0.001-0.043). Even with preserved left ventricle (LV) ejection fraction, peak longitudinal and radial velocities of the LV are reduced in AS and HYP, indicating early functional impairment. J. Magn. Reson. Imaging 2016;44:168-177.

Acute respiratory distress syndrome (ARDS)-associated acute cor pulmonale and patent foramen ovale: a multicenter noninvasive hemodynamic study.

IntroductionAcute cor pulmonale (ACP) and patent foramen ovale (PFO) remain common in patients under protective ventilation for acute respiratory distress syndrome (ARDS). We sought to describe the hemodynamic profile associated with either ACP or PFO, or both, during the early course of moderate-to-severe ARDS using echocardiography.MethodsIn this 32-month prospective multicenter study, 195 patients with moderate-to-severe ARDS were assessed using echocardiography during the first 48 h of admission (age: 56 (SD: 15) years; Simplified Acute Physiology Score: 46 (17); PaO2/FiO2: 115 (39); VT: 6.5 (1.7) mL/kg; PEEP: 11 (3) cmH2O; driving pressure: 15 (5) cmH2O). ACP was defined by the association of right ventricular (RV) dilatation and systolic paradoxical ventricular septal motion. PFO was detected during a contrast study using agitated saline in the transesophageal bicaval view.ResultsACP was present in 36 patients, PFO in 21 patients, both PFO and ACP in 8 patients and the 130 remaining patients had neither PFO nor ACP. Patients with ACP exhibited a restricted left ventricle (LV) secondary to RV dilatation and had concomitant RV dysfunction, irrespective of associated PFO, but preserved LV systolic function. Despite elevated systolic pulmonary artery pressure (sPAP), patients with isolated PFO had a normal RV systolic function. sPAP and PaCO2 levels were significantly correlated.ConclusionsIn patients under protective mechanical ventilation with moderate-to-severe ARDS, ACP was associated with LV restriction and RV failure, whether PFO was present or not. Despite elevated sPAP, PFO shunting was associated with preserved RV systolic function.

Apical Hypertrophic Cardiomyopathy.

To the Editor We have read with interest the excellent review on hypertrophic cardiomyopathy (HCM)1 and wish to comment on the apical variant of the disease listed in Table 4 but not discussed in the text. This variant can be found in 15% to 25% of Chinese and Japanese cohorts with HCM but only in 3% of American cohorts.2 The typical electrocardiography (ECG) shows the loss of septal Q waves, high QRS voltage, and repolarization abnormalities with deep T-wave inversion, especially in the leads closest to the apex—V4–V6.2 Because hypertrophy is confined to the apex, dynamic left ventricular outflow tract obstruction and systolic anterior motion of the anterior mitral valve leaflet are absent. The apical pulse may be sustained on palpation, and an S4 heart sound may be heard.2 There may not be a systolic murmur. It is reasonable to expect some degree of diastolic dysfunction and the possibility of relative apical ischemia as a result of the unbalanced wall thickness-to-vascular supply ratio.3 HCM apical variant may not have a totally benign prognosis with atrial fibrillation and myocardial infarction occurring in up to one-third of patients during long-term follow-up in the Western population.3,4 In addition, in patients with atrial fibrillation, HCM (including the apical variant) may increase the risks of systemic thromboembolism and the need for long-term anticoagulation.5,6 However, there are currently no data to suggest that the perioperative risks are increased in afflicted patients without a history of syncope, chest pain, dyspnea, or heart failure. Nonetheless, in a young asymptomatic patient, the bizarre ECG pattern first seen when intraoperative ECG electrodes are placed can be alarming and may even lead to the postponement of surgery or initiation of coronary vasodilator treatment. Alternatively, a preoperative ECG may lead one to suspect HCM. However, plain echocardiography may still miss apical HCM if the apex is not adequately examined.3 A microbubble contrast-enhanced echocardiography or cardiac magnetic resonance imaging, or both, may be required to differentially diagnose apical HCM, coronary artery disease, myocardial tumor, ventricular aneurysm, ventricular noncompaction, or endomyocardial fibrosis.3 Anthony M. H. Ho, MD, FRCPC, FCCP Department of Anesthesiology and Perioperative Medicine Queen’s University and Kingston General Hospital Kingston, Ontario, Canada [email protected] Po T. Chui, MBBS, FANZCA Alex P. W. Lee, MBChB, MRCP Song Wan, PhD, MD, FRCS Departments of Anaesthesia and Intensive Care, Medicine & Therapeutics, and Surgery The Chinese University of Hong Kong and Prince of Wales Hospital Hong Kong SAR, People’s Republic of China

Intraoperative improvement in left ventricular peak systolic velocity predicts better short-term outcome after transcatheter aortic valve implantation.

Left ventricular function is expected to improve after transcatheter aortic valve implantation due to the acute reduction in afterload, but does not occur in all patients. We hypothesized that the immediate intraoperative response in systolic left ventricular longitudinal motion during the procedure could be a predictor of short-term outcome. Sixty-four patients treated with transcatheter aortic valve implantation for severe aortic stenosis were included. Transoesophageal 4- and 2-chamber echocardiograms were obtained immediately prior to and ∼15 min after valve implantation. Patients were defined as responders if their average left ventricular longitudinal peak systolic velocity increased by ≥20% from the preimplantation value and was related to the 3-month outcome. Thirty-five patients were classified as responders, with an increase in the intraoperative longitudinal peak systolic velocity from an average of 2.2 ± 0.8 to 3.1 ± 1.1 cm/s (P < 0.001); the velocity was unchanged in the remaining 29 patients, who averaged 2.4 ± 1.1 cm/s. There were significantly fewer adverse cardiac events in the responder group at the 3-month follow-up (20 vs 45%, P = 0.03) and the New York Heart Association class was significantly better in the responders compared with non-responders. Responders had a significant reduction in N-terminal probrain natriuretic peptide levels [243 (113-361) vs 163 (64-273), P = 0.004] at the 3-month follow-up, whereas non-responders did not [469 (130-858) vs 289 (157-921), P = 0.48]. An immediate improvement in the longitudinal peak systolic velocity during the transcatheter aortic valve implantation procedure predicted a better short-term outcome and may be useful in identifying patients who are at risk of a less favourable outcome after transcatheter aortic valve implantation.

Treatment of secondary mitral valve regurgitation: why we need combined and evolving percutaneous strategies to tackle this moving target.

Secondary mitral regurgitation (MR) has a complex pathophysiology that includes global or segmental left ventricular (LV) motion abnormalities (of non-ischaemic or ischaemic origin) leading to impaired leaflet coaptation of a normally structured mitral valve (MV). In this context, the LV functional and geometrical changes result in MV leaflet tethering, MV annulus flattening and the decrement of systolic MV closing forces. In light of its complexity, management of secondary MR remains a challenge. In fact, a long-lasting successful treatment using a single medical device and/or intervention that addresses solely the MV target cannot, at least at the present time, be proposed.

Integration of Multi-Plane Tissue Doppler and B-Mode Echocardiographic Images for Left Ventricular Motion Estimation.

Although modern ultrasound acquisition systems allow recording of 3D echocardiographic images, tracking anatomical structures from them is still challenging. In addition, since these images are typically created from information obtained across several cardiac cycles, it is not yet possible to acquire high-quality 3D images from patients presenting varying heart rhythms. In this paper, we propose a method to estimate the motion field from multi-plane echocardiographic images of the left ventricle, which are acquired simultaneously during a single cardiac cycle. The method integrates tri-plane B-mode and tissue Doppler images acquired at different rotation angles around the long axis of the left ventricle. It uses a diffeomorphic continuous spatio-temporal transformation model with a spherical data representation for a better interpolation in the circumferential direction. This framework allows exploiting the spatial relation among the acquired planes. In addition, higher temporal resolution of the transformation in the beam direction is achieved by uncoupling the estimation of the different components of the velocity field. The method was validated using a realistic synthetic dataset including healthy and ischemic cases, obtaining errors of 0.14 ± 0.09 mm for displacements, 0.96 ± 1.03% for longitudinal strain and 3.94 ± 4.38% for radial strain estimation. In addition, the method was also demonstrated on a healthy volunteer and two patients with ischemia.

FLUID DYNAMIC CHARACTERISTICS OF SYSTOLIC BLOOD FLOW OF THE LEFT VENTRICLE

Ejection of blood from the left ventricle to the aorta is studied using two-dimensional Navier–Stokes equations, the work-energy equation and the magnetic resonance imaging of a normal ventricular motion. Vortex shedding in the sinuses of Valsalva is dominated by the aortic jet, flow acceleration and valve motion. Momentums produced by ventricular contraction are in concert with vortices in the ventricle for blood ejection. Shear stresses and net pressures on the aortic valve are calculated during valve opening and closing. The rate of work done by shear and the energy dissipation in the ventricle are small. The Bernoulli energy flux delivered to blood from ventricular contraction is practically balanced by energy flux at the aortic root and the rate change of kinetic energy in the ventricle.

Reply to the editorial comment from Van der Wall concerning 'The right ventricle: always normal in normal subjects?'.

To the Editor, We read the comment referring to the challenges in imaging the right ventricle with great interest [1]. The difficulties in distinguishing wall motion abnormalities in healthy subjects from those in diseased patients are very well summarised. The author cites the article by Doesch et al. [2] presenting 20 healthy subjects with CMR-derived measurement of the tricuspid annular plane systolic excursion (TAPSE) with a reference point outside the ventricle (TAPSEout), which might be used for screening right ventricular motion. We could demonstrate TAPSE in cardiac magnetic resonance (CMR), being a fast and easily obtainable parameter correlating well to volumetric quantification of right ventricular ejection fraction (RVEF), with low interobserver and intraobserver variables. Therefore, we investigated 76 patients (age: 58 ± 17 years) with mean RVEF of 42 ± 14 %, assessed by the standardised slice-summation method. CMR-TAPSE was determined to be 19 ± 6 mm and correlated well in linear regression analysis with volumetric RVEF (r = 0.72, p < 0.001). However, we could also show that CMR-TAPSE is not only a fast tool in healthy subjects, but it also discriminates well between patients with impaired and normal RVEF. Multiplying CMR-TAPSE measurements by 2.5 leads to values close to the RVEF by volumetry. Furthermore, CMR-TAPSE correlates well with TAPSE determined using transthoracic echocardiography [3].

Echocardiographic study of left ventricular three-dimensional, radial and longitudinal displacement during base condition in vivo: a canine model

Objective To evaluate the changes of left ventricular myocardial peak 3-dimensional displacement(3D-D), radial displacement(RD) and longitudinal displacement(LD) during baseline patterns, and provide a reliable and appropriate mechanical database for myocardial structure and function. Methods Left ventricular 3D full volumetric real-time imaging in open-chest Beagle canine models(n=10) were acquired in a complete cardiac cycle. The 3D-D, RD and LD for differences and rules were calculated and analyzed by speckle tracking imaging. Results ① There were not difference between 3D-D and RD at baseline patterns with all segments(P>0.05). There were significant difference between 3D-D and LD at baseline patterns with all segments(P 0.05). There were significant difference between 3D-D and LD at baseline patterns with the global(P<0.01). There were significant difference between LD and RD at baseline patterns with the global(P<0.01). ③ There were significant correlation between 3D-D and the most segments of RD(P<0.01). There were correlation between 3D-D and the partly segments of LD (P<0.05). There were correlation between the partly segments of RD and LD(P<0.05). Conclusions Echocardiographic study of left ventricular 3D-D can actually reveal myocardial mechanics and strcture during baseline patterns. 3D-D can accurately reflect left ventricular motion condition. The changes of myocardial mechanics mainly depends on the radial motion.Left ventricular RD can be more accurately reflection on myocardial motion state than LD. Key words: Echocardiography, real-time three-dimensional; Ventricular function, left; Displacement

Assessment of regional myocardial work in rats.

Left ventricular (LV) motion and deformation is dependent on mechanical load and do therefore not reflect myocardial energy consumption directly. Regional myocardial work, however, constitutes a more complete assessment of myocardial function. Strain was measured using high-resolution phase-contrast MRI in 9 adult male rats with myocardial infarction (MI) and in 5 sham-operated control animals. Timing of LV valvular events and LV dimensions were evaluated by cine MRI. A separate cohort of 14 animals (MI/sham=9/5) underwent measurement of LV pressure concurrent with identification of valvular events by Doppler-echocardiography for the purpose of generating a standard LV pressure curve, normalized to valvular events. The infarctions were localized to the anterolateral LV wall. Combining strain with timing of valvular events and a measurement of peak arterial pressure, regional myocardial work could be calculated by applying the standard LV pressure curves. Cardiac output and stroke work was preserved in the MI hearts, suggesting a compensatory redistribution of myocardial work from the infarcted region to the viable tissue. In the septum, regional work was indeed increased in MI rats compared with sham (median work per unit long-axis length in a mid-ventricular slice: 241.2 [224.1-271.2] versus 137.2 [127.0-143.8] mJ/m; P<0.001). Myocardial work in infarcted regions was zero. Additionally, eccentric work was increased in the MI hearts. Phase-contrast MRI, in combination with measurement of peak arterial pressure and MRI-derived timing of valvular events, represent a noninvasive approach for estimation of regional myocardial work in rodents.

Intraindividual comparison of circumferential strain using speckle tracking by echocardiography versus CMR feature tracking and myocardial tagging in patients

Background Left ventricular myocardial motion analysis and the assessment of regional dysfunction are crucial for the detection and prognosis in different cardiac pathologies. Myocardial tagging (MT) is a cardiac magnetic resonance (CMR) based method for tracking myocardial motion, which has been established as reference standard for assessment of strain. Currently, strain can also be assessed by CMR using feature tracking (FT) or by echocardiography with speckle tracking (ST). Aim of our study was to evaluate intraindividually and compare myocardial circumferential strain (Ecc) using MT, FT and ST.

Left ventricular motion quantification parameters from tissue phase mapped MRI: influence of gender

Background Several motion parameters for quantification of LV motion abnormalities and asynchrony have been described in literature, but were investigated with different acquisition protocols and for different cohorts, thus impeding comparability. For derivation of normal values in healthy volunteers, calculation of all parameters from a single acquisition protocol is desirable. In this study, influence of gender on the motion parameters is investigated in order to determine the necessity of separate female/male normal values.

Transcatheter aortic valve implantation and intraoperative left ventricular function: a myocardial tissue Doppler imaging study.

Transcatheter aortic valve implantation in patients turned down for surgical aortic valve replacement is a high-risk procedure. Severe aortic stenosis is associated with impaired left ventricular longitudinal motion, and myocardial peak systolic velocity is a measure of left ventricular function in these patients. The present study aimed to quantify the acute changes in left ventricular function during the procedure by using myocardial tissue Doppler imaging and transthoracic cardiac output measurements. Prospective observational study. Tertiary care university hospital. 40 patients with severe aortic stenosis scheduled for transcatheter aortic valve implantation. Transesophageal 4-chamber and 2-chamber echocardiograms were performed immediately before and ~15 minutes after valve implantation. Longitudinal myocardial peak systolic velocity was obtained by tissue Doppler imaging from 8 basal segments and averaged. Cardiac output was measured by the lithium dilution method, and systemic vascular resistance index and stroke volume were calculated. Longitudinal myocardial peak systolic velocity improved immediately after valve implantation, from -2.3±0.8 to -3.0±1.1 cm/sec (p<0.001); this represented an average increase of 31%±33%. Cardiac output increased from 3.2±0.8 L/min to 3.6±0.9 L/min (15%±33%; p = 0.04). This was due to increased heart rate (59±9 beats/min to 72±12 beats/min; p<0.001) and not to an improved stroke volume. Systemic vascular resistance index was reduced from 2,937±984 dynes*sec/cm(5)/m(2) to 2,436±730 dynes*sec/cm(5)/m(2) (p = 0.003). Intraoperative echocardiography tissue Doppler imaging detected immediate improvement in left ventricular long-axis motion after transcatheter aortic valve implantation. The method provided detailed information not obtainable by routine hemodynamic monitoring.

Right ventricular myocardial motion and deformation in adolescents and young adults after repair of coarctation of the aorta.

Alteration of right ventricular (RV) function has been found in patients with pressure-loaded left ventricles due to systemic hypertension and aortic stenosis. We tested the hypothesis that RV mechanics are altered in adolescents and adults with repaired coarctation of the aorta (CoA). Twenty-eight (15 male) patients, aged 23.7 ± 6.5 years, and 28 (14 male) controls were studied. M-mode, tissue Doppler imaging, and speckle tracking echocardiography were performed to assess, respectively, LV mass and RV wall thickness, RV myocardial tissue velocities, and deformation. Systolic (P = 0.14) and diastolic (P = 0.32) blood pressures were similar between patients and controls. Compared with controls, patients had significantly greater LV mass (P = 0.016) and RV anterior wall thickness (P = 0.012). Tricuspid annular systolic (P < 0.001) and early diastolic (P < 0.001) velocities, isovolumic acceleration (P = 0.004), global RV systolic longitudinal strain (P = 0.03), systolic strain rate (P = 0.012), and early (P = 0.021) and late (P = 0.012) diastolic strain rates were significantly lower in patients than controls. Patients with an associated ventricular septal defect (n = 6) requiring closure compared to those without had even lower tricuspid annular systolic (P = 0.01) and early diastolic (P = 0.041) velocities. Left ventricular mass correlated negatively with RV systolic strain rate (r = -0.27, P = 0.045) and tricuspid annular early diastolic velocity (r = -0.40, P = 0.002), while RV anterior wall thickness correlated negatively with tricuspid annular systolic (r = -0.42, P = 0.002) and late diastolic (r = -0.40, P = 0.003) velocities, and positively with e/a ratio (r = 0.31, P = 0.024). RV systolic and diastolic mechanics are impaired in patients late after repair of CoA and related to increased LV mass and RV thickness.

The association between left ventricular twisting motion and mechanical dyssynchrony: a three-dimensional speckle tracking study.

Left ventricular (LV) dyssynchrony is a causal factor in LV dysfunction and thought to be associated with LV twisting motion. We tested whether three-dimensional speckle tracking (3DT) can be used to evaluate the relationship between LV twisting motion and dyssynchrony. We examined 25 patients with sick sinus syndrome who had received dual chamber pacemakers. The acute effects of ventricular pacing on LV wall motion after the switch from atrial to ventricular pacing were assessed. LV twisting motion and dyssynchrony during each pacing mode were measured using 3DT. LV dyssynchrony was calculated from the time to the minimum peak systolic area strain of 16 LV imaging segments. Ventricular pacing increased LV dyssynchrony and decreased twist and torsion. A significant correlation was observed between changes in LV dyssynchrony and changes in torsion (r = -0.65, p < 0.01). Evaluation of LV twisting motion can potentially be used for diagnosing LV dyssynchrony.

Tissue Doppler imaging and ultrasonic methods for evaluating myocardial deformation in the diagnosis of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disease caused by mutations in genes that encode components of the sarcomere. Standard echocardiography is not always capable to identify regional systolic dysfunction of the left ventricle (LV), and to detect the disease on its preclinical stage. Genetic testing allows identifying sarcomere gene mutations in less than 50% of patients due to difficulty of screening all genes responsible for hypertrophic cardiomyopathy. Modern innovative methods of echocardiography - tissue Doppler, strain and strain rate, speckle tracking have been widely used for quantification of regional ventricular motion. Work of recent decades has proven the ability of these techniques to detect regional systolic and diastolic dysfunction of the LV, to diagnose HCM early, to differentiate it from other pathological and physiological hypertrophies. These modes can be used for prediction of cardiovascular complications in patients with HCM. In clinical practice the use of innovative technologies in combination with standard echocardiography allows to obtain more accurate and extensive information on the severity and prognosis of the disease.