Left Ventricular Lateral Wall Research Articles

Left Ventricular Myocardial and Hemodynamic Response to Exercise in Young Patients after Endovascular Stenting for Aortic Coarctation

Endovascular stenting has emerged as a treatment option for children with coarctation of the aortic (CoA), but the impact on left ventricular (LV) function has been poorly documented. The aim of this study was to characterize the LV myocardial and hemodynamic response to exercise in young patients who underwent endovascular stenting for CoA during childhood using semisupine bicycle exercise stress echocardiography. This was a single-center prospective cross-sectional study including 30 patients with CoA and 30 age- and gender-matched control subjects who underwent semisupine bicycle exercise stress echocardiography. Color Doppler tissue imaging peak systolic (s') and early diastolic (e') velocities in the LV lateral wall and basal septum, LV myocardial acceleration during isovolumic acceleration were measured at rest and with incremental heart rate (HR). The relationship with increasing HR was evaluated for each parameter by plotting the values at each stage of exercise versus HR. At rest, HR was similar between the two groups. LV ejection fraction and fractional shortening were within the normal range in the CoA group. LV lateral wall and basal septal s' and e' velocities did not differ between the two groups, but isovolumic acceleration values were significantly lower in the CoA group. At peak exercise, HR was similar between the groups, but all Doppler tissue imaging parameters were lower in patients than in control subjects. When assessing the increase of each parameter versus HR, the increase in slope was significantly lower in patients than in control subjects for LV lateral wall Doppler tissue imaging s' and e' velocities, and septal e' velocity, but not for septal s'. The relationship of isovolumic acceleration with HR was significantly reduced in the CoA group. The results of this study demonstrate reduced systolic and diastolic myocardial reserve in patients with CoA compared with control subjects. An abnormal myocardial contractile response to exercise was also found, as shown by an abnormal LV force-frequency relationship in patients with stented CoA. The prognostic clinical implications require further study.

Early Effect of Surgical Revascularisation on Left Ventricular Twist Function

<p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p><p style="margin: 0cm 0cm 10pt; text-align: justify;"><span style="font-family: 'Times New Roman','serif';"><span style="font-size: medium;">The direct effect of coronary artery bypass graft (CABG) surgery on early recovery of myocardial function, particularly twist and rotation is not well studied. </span></span></p><p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p><p style="margin: 0cm 0cm 10pt; text-align: justify;"><span style="font-family: 'Times New Roman','serif';"><span style="font-size: medium;">Aim: To assess the early response of the 3 myocardial components, circumferential, longitudinal and oblique to CABG in patients with isolated coronary disease.</span></span></p><p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p><p style="margin: 0cm 0cm 10pt; text-align: justify;"><span style="font-family: 'Times New Roman','serif';"><span style="font-size: medium;">Methods: We studied 14 patients, age 64±10 years, before CABG and before hospital discharge using various Doppler echocardiographic techniques including speckle tracking, and compared them with 28 age matched controls.</span></span></p><p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p><p style="margin: 0cm 0cm 10pt; text-align: justify;"><span style="font-family: 'Times New Roman','serif';"><span style="font-size: medium;">Results: Before surgery: Compared to controls, patients had significantly reduced LVEF (p=0.01) but maintained stroke volume (SV) (p=0.5). Diastolic LV function indices were statistically abnormal (p=0.01). LV lateral wall long axis amplitude and myocardial systolic velocities were both reduced (p=0.01) as was septal amplitude of motion (p=0.05). LV peak global longitudinal strain (GLS) was reduced as were systolic and early diastolic global longitudinal strain rates (p=0.01 for all). LV peak basal and apical rotations, twist and torsion were not different. Q-peak basal rotation was shorter than controls (p=0.01).</span></span></p><p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p><p style="margin: 0cm 0cm 10pt; text-align: justify;"><span style="font-family: 'Times New Roman','serif';"><span style="font-size: medium;">After surgery: None of these measurements changed except peak GLS which further reduced (p=0.01). Pre-operatively, SV correlated with global LV function: twist (r= -0.65, p=0.01), and LV torsion (r=-0.66, p=0.01) but LVEF did not correlate with either. Post-operatively, SV correlated with E/A ratio (r=0.66, p=0.01), and the time interval Q- peak basal rotation rate (r=0.8, p=0.002).</span></span></p><p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p><p style="margin: 0cm 0cm 10pt; text-align: justify;"><span style="font-family: 'Times New Roman','serif';"><span style="font-size: medium;">Conclusion: CABG does not result in significant early segmental LV functional improvement along its three myocardial components, but SV becomes dependent on early basal rotation and filling pressures.</span></span></p><p style="margin: 0cm 0cm 10pt; text-align: justify;"> </p>

Identifying delayed left ventricular lateral wall activation in patients with non-specific intraventricular conduction delay using coronary venous electroanatomical mapping.

BackgroundDelayed left ventricular (LV) lateral wall activation is considered the electrical substrate that characterises patients suitable for cardiac resynchronisation therapy (CRT). Although typically associated with left bundle branch block, delayed LV lateral wall activation may also be present in patients with non-specific intraventricular conduction delay (IVCD). We assessed LV lateral wall activation in a cohort of CRT candidates with IVCD using coronary venous electroanatomical mapping, and investigated whether baseline QRS characteristics on the ECG can identify delayed LV lateral wall activation in this group of patients.MethodsTwenty-three consecutive CRT candidates with IVCD underwent intra-procedural coronary venous electroanatomical mapping using EnSite NavX. Electrical activation time was measured in milliseconds from QRS onset and expressed as percentage of QRS duration. LV lateral wall activation was considered delayed if maximal activation time measured at the LV lateral wall (LVLW-AT) exceeded 75 % of the QRS duration. QRS morphology, duration, fragmentation, axis deviation, and left anterior/posterior fascicular block were assessed on baseline ECGs.ResultsDelayed LV lateral wall activation occurred in 12/23 patients (maximal LVLW-AT = 133 ± 20 ms [83 ± 5 % of QRS duration]). In these patients, the latest activated region was consistently located on the basal lateral wall. QRS duration, and prevalence of QRS fragmentation and left/right axis deviation, and left anterior/posterior fascicular block did not differ between patients with and without delayed LV lateral wall activation.ConclusionCoronary venous electroanatomical mapping can be used at the time of CRT implantation to determine the presence of delayed LV lateral wall activation in patients with IVCD. QRS characteristics on the ECG seem unable to identify delayed LV lateral wall activation in this subgroup of patients.

Evaluation of Trastuzumab-induced early cardiac dysfunction using two-dimensional Strain Echocardiography.

Trastuzumab, a chemotherapeutic agent used in the treatment of breast cancer. has been shown to induce subclinical left ventricular (LV) dysfunction during a three to six month period as evidenced by strain echocardiographic examination without any change occurring in the ejection fraction of LV. The present study evaluated the presence of subclinical LV dysfunction using strain echocardiography 1 day and 7 days after the initiation of trastuzumab therapy. The patients with breast cancer receiving adjuvant trastuzumab therapy underwent 2-dimensional, tissue Doppler, and strain echocardiographic examination at baseline and 1 day and 7 days after therapy. LV global longitudinal strain (GLS), global circumferential strain (GCS) values, and other echocardiographic parameters were calculated. A total of 40 females, mean age 50+/-10 years, were evaluated. Of these patients, 97% received anthracycline and 73% received radiotherapy before the initiation of trastuzumab therapy. No change was observed in any of the echocardiographic parameters 1 day after the initiation of trastuzumab therapy (p>0.05). The LV ejection fraction, tissue Doppler parameters, and GCS values did not show any changes 7 days after the initiation of therapy, whereas significant decreases were observed in GLS value (19.2+/-4.0% vs. 17.2+/-3.4, p=0.001) and systolic annular velocity of the lateral LV wall (S' velocity) (10.5+/-3.2 vs. 8.6+/-2.2, p=0.002). Trastuzumab therapy is associated with subclinical LV dysfunction as early as 7 days after initiation of the therapy as evidenced by the decreases in GLS value of LV and systolic annular velocity of the lateral LV wall.

Abstract 15325: Chromogranin B Levels are Increased in Myocardial Tissue in the Dyssynchronous Left Ventricle and Relate to Abnormalities in Regional Myocardial Deformation

Introduction: Left bundle branch block (LBBB) induces abnormal activation and deformation of the LV wall. Chromogranin B (CgB) levels are increased in myocardium and plasma of heart failure patients and are linked to cardiomyocyte Ca 2+ handling. Hypothesis: That CgB expression is increased in distinct LV regions during LBBB and may be related to regional deformation abnormalities. Methods: CgB and pro-B-type natriuretic peptide (proBNP) protein levels were measured in biopsies from septum and LV lateral wall in 6 dogs with chronic LBBB (16 weeks), 8 control animals, and in 8 dogs with LBBB that received cardiac resynchronization therapy (CRT) between 8 and 16 weeks after creation of LBBB. Regional myocardial strain was assessed by speckle tracking echocardiography, LV volumes by MRI, and hemodynamics were assessed by invasive pressure measurements (LV dP/dt max and min, tau , LVP max and min, and LV end-diastolic pressure). Results: LBBB animals had increased end-diastolic volumes (55±1 vs.45±4 mL, p=0.038) but normal LV ejection fraction (50±3 vs. 55±4 %, p=0.42) compared to control animals. CgB levels were increased in both septum (p<0.001) and LV lateral wall (p=0.01) in LBBB compared to controls, despite no changes in LV proBNP levels, and with the most prominent increment found in the septum (Figure). In LBBB+CRT animals, CgB levels were 36±18% (septum) and 50±11% (LV later wall) lower compared to LBBB animals, but this difference was not statistically significant. Septal CgB levels correlated with septal early systolic rebound stretch (r=0.76, p=0.017) and lateral wall CgB levels with lateral wall pre-ejection stretch (r=0.76, p=0.018), while no correlations were found with LV dimensions or indices of global hemodynamic function. Conclusion: Myocardial CgB expression was increased in the absence of elevated proBNP levels in LBBB animals with preserved systolic function. Local CgB levels appear to relate to abnormal local early-systolic mechanical loading.

Abstract 12002: Increasing Heart Rate in Left Bundle Branch Block Results in Incomplete Relaxation and Increases Left Ventricular Diastolic Stiffness

Introduction: Left bundle branch block (LBBB) slows LV pressure decay and shortens diastole. At low heart rates (HR) this may not compromise filling as diastolic duration is sufficient for complete relaxation. Purpose: We investigated if further abbreviation of diastole at increased HR could cause incomplete relaxation, particularly in the late activated LV lateral wall; thereby increasing diastolic LV stiffness, which may cause increased filling pressure. Methods: We analyzed data from a study of 10 canines where HR was increased from 120 to 140 by atrial pacing before and after induction of LBBB. Ventricular and pericardial pressures, LV volume and regional segment lengths (SL) were measured. Global diastolic stiffness was calculated from end diastolic (ED) transmural LV pressure-volume (PV) relations and regional stiffness from pressure-SL relations in septum and lateral wall. A mathematical model was used to estimate the increase in filling pressure due to incomplete relaxation at HR 160 and 180. Results: In LBBB, tau was prolonged and diastole abbreviated at both HR 120 and 140, compared to baseline (Fig. 1). Increased HR during LBBB stiffened the ventricle, seen as an upward shift of the ED PV relation by 1.4±1.7 mmHg (±SD), (p=0.03) whereas no shift (-0.9±1.5 mmHg) (NS) was seen at baseline (Fig. 2). Regional ED P-SL relations showed a larger upward shift of the lateral wall (1.1±1.8 mmHg) and hence a more pronounced stiffening compared to the septum (0.6±1.5 mmHg) (p<0.05), indicating more delayed lateral wall relaxation. Mathematical estimation showed an increase in filling pressure of 7 and 16 mmHg due to further diastolic abbreviation at HR 160 and 180, respectively. Conclusions: LV diastolic stiffness is increased at high heart rates in LBBB due to incomplete relaxation, particularly of the late activated LV lateral wall. Diastolic stiffening by increased HR may lead to exercise intolerance and dyspnoea in LBBB patients due to elevated filling pressure.

Abstract 9952: Myocardial PtiO2 is a More Reliable Variable Than FFR, Showing High Potential for Clinical Application in Assessing Myocardial Ischemia Caused by Coronary Artery Stenosis

Background: A patient of effort angina who had 75% stenosis at #7 with high FFR 0.85 underwent PCI. He has had no chest pain at all since PCI. Purpose: To find a more reliable variable than FFR in assessing myocardial ischemia (MI) caused by coronary artery stenosis (CAS), animal experiments were done to cover three variables - coronary blood flow (Flow), myocardial PtiO2 (PtiO2) and FFR, which were compared to see which is the most reliable of the three. All the procedures were approved by Clinic’s ethical committee and carried out observing the Declaration of Helsinki of the World Medical Association. Method: In twelve pigs, vascular occuluders and flow meters were set at #6 and/or #7 and #11 and/or #13. PtiO2 sensor wires were inserted into the anterior and lateral LV wall transepicardially. FFR sensor wires were placed across the LAD and LCX stenoses. The data was all analyzed by a paired t-test and ROC. Results: Flow(ml/min): normal 54.23±5.24 and 50% 27.88±5.53, p< 0.0001; sencitivity(sen.) 1.00, specificity(spe.) 1.00, accuracy(acc.) 1.00 by ROC 38.9. 50% and 75% 17.60±6.06, p < 0.0001; sen. 0.92, spe. 0.83, acc. 0.88 by ROC 21.8. PtiO2(mmHg) : normal 54.91±6.44 and 50% 27.87±3.40, p< 0.0001; sen. 1.00, spe 1.00, acc. 1.00 by ROC 32.1. 50% and 75% 16.85±2.73, p < 0.0001; sen. 0.92, spe. 0.92, acc. 0.92 by ROC 21.7. FFR: normal 0.97±0.01 and 50% 0.89±0.06, p < 0.0001; sen. 0.92, spe. 1.0, acc. 0.96 by ROC 0.96. 50% and 75% 0.83±0.04. p < 0.0002; sen. 0.75, spe. 0.75, acc. 0.75 by ROC 0.86. Thus PtiO2 was the most reliable variable in assessing MI of CAS among three. To confirm clinical application of PtiO2 , animal experiments using ten pigs was conducted to measure it through coronary artery. 0.5 mm transepicardial sensor wires were attached to the tips of upside-down 0.014 inch guiding wires. The guiding wires perforated LADs and were pushed into myocardium to measure PtiO2 (normal 55.54±3.57, 50% 28.08±2.48, 75% 17.1±2.85). These data showed no significant difference from the transepicardial data described above. A leak of contrast agent through a tiny perforation had expired in ten minutes. Conclusion: The results proved PtiO2 was the more reliable valiable than FFR, showing high potential for clinical application in safely assessing MI caused by CAS.

Left ventricular myxoma

A 31 year-old woman complaining of mild dyspnea and fatique was admitted to our clinic.A two-dimensional echocardiogram revealed a 2×2 cm mobile mass in the left ventricle. A 2 x 3 cm mobile,pedinculated,gelatinous mass originating from the left ventricular lateral wall was removed by left ventriculotomy and histological features of the tumor indicated a myxoma.

Cardiac systolic regional function and synchrony in endurance trained and untrained females

BackgroundMost studies on cardiac function in athletes describe overall heart function in predominately male participants. We aimed to compare segmental, regional and overall myocardial function and synchrony in female endurance...

Percutaneous Management of a Coronary Bifurcation Aneurysm with Mesh-Covered Stents and the Simultaneous Kissing Stent Technique

A 63-year-old man was admitted with a clinical diagnosis of acute coronary syndrome (non-ST-segment elevation), characterized by regional hypokinesia of the left ventricular posterior and lateral walls and by positive cardiac biomarkers. The coronary angiogram showed a 12.5-mm-diameter aneurysm with a mural thrombus and possible distal embolism to the bifurcation of the left circumflex coronary artery and the 2nd marginal branch. The aneurysm was managed percutaneously by implanting 2 mesh-covered stents in accordance with the "simultaneous kissing stent" technique. Follow-up angiography and optical coherence tomography at 5 postprocedural months documented complete sealing of the aneurysm and diffuse in-stent restenosis. No sign of ischemia occurred during the subsequent follow-up.

Vectorcardiographic QRS area identifies delayed left ventricular lateral wall activation determined by electroanatomic mapping in candidates for cardiac resynchronization therapy

Delayed left ventricular (LV) lateral wall (LVLW) activation is considered the electrical substrate underlying LV dysfunction amenable to cardiac resynchronization therapy (CRT). The purpose of this study was to assess LVLW activation in CRT candidates using coronary venous electroanatomic mapping (EAM) and to investigate whether the QRS area (QRSAREA) on the vectorcardiogram (VCG) can identify delayed LVLW activation. Fifty-one consecutive CRT candidates (29 left bundle branch block [LBBB], 15 intraventricular conduction delay [IVCD], 7 right bundle branch block [RBBB]) underwent intraprocedural coronary venous EAM using EnSite NavX. VCGs were constructed from preprocedural digital 12-lead ECGs using the Kors method. QRSAREA was assessed and compared to QRS duration and 5 different LBBB definitions. Delayed LVLW activation (activation time >75% of QRS duration) occurred in 38 of 51 patients (29/29 LBBB, 8/15 IVCD, 1/7 RBBB). QRSAREA was larger in patients with than in patients without delayed LVLW activation (108 ± 42 µVs vs 51 ± 27 µVs, P < .001), and identified delayed LVLW activation better than QRS duration (area under the curve 0.89 [95% confidence interval 0.79-0.99] vs 0.49 [95% confidence interval 0.33-0.65]). QRSAREA >69 µVs diagnosed delayed LVLW activation with a higher sum of sensitivity (87%) and specificity (92%) than any of the LBBB definitions. Of the different LBBB definitions, the European Society of Cardiology textbook definition performed best with sensitivity of 76% and specificity of 100%. Coronary venous EAM can be used during CRT implantation to determine the presence of delayed LVLW activation. QRSAREA is a noninvasive alternative for intracardiac measurements of electrical activation, which identifies delayed LVLW activation better than QRS duration and LBBB morphology.

Assessment of ventricular function in adults with repaired Tetralogy of Fallot using myocardial deformation imaging.

Many patients with repaired Tetralogy of Fallot (ToF) have right ventricular (RV) volume overload due to pulmonary regurgitation (PR). We studied the effect of volume overload on global and regional RV and left ventricular (LV) deformation, and their relationships with conventional diagnostic parameters. In this cross-sectional study, 94 prospectively recruited ToF patients (61% male, age 32.8 ± 9.5 years, age at repair 1.9 [0.8-5.7] years, 39% pulmonary homograft) and 85 healthy controls of similar age and sex underwent echocardiography and electrocardiography. In a subset of patients, cardiac magnetic resonance imaging, bicycle ergometry, and NT-proBNP measurement were performed within the same day. With speckle-tracking echocardiography, we analysed peak systolic global longitudinal strain (GLS), segmental longitudinal strain and strain rate of the RV free wall, LV lateral wall, and septum. Patients had a lower RV free wall strain than controls (-18.1 ± 4.5 vs. -26.5 ± 4.5%, P < 0.001), especially at the apical segment (-15.9 ± 7.4 vs. -28.2 ± 7.7%, P < 0.001), and lower RV strain rate. LV GLS was also lower (-17.4 ± 2.5 vs. -19.6 ± 1.9%, P < 0.001), mainly due to the interventricular septum. Patients with PR >25% had higher LV GLS and RV free wall strain than patients with PR ≤25% (P = 0.004, P = 0.039, respectively). No relationships were found with NT-proBNP or exercise capacity. RV free wall strain and strain rate are decreased in adults late after ToF repair, especially at the apical segment suggesting that apical function is most affected in these RVs. Regarding the LV, septal strain is decreased indicating that RV dysfunction adversely affects LV function, probably by mechanical coupling of the ventricles.

Evaluation of the ventricular systolic function in dogs with pulmonary artery hypertension after transcatheter renal sympathetic denervation

Objective To evaluate the effects of transcatheter renal sympathetic denervation (RSD) on the cardiac systolic function of dogs with pulmonary arterial hypertension(PAH) using two-dimensional speckle tracking imaging(2D-STI). Methods Twenty two dogs were divided in to three groups: control group (n=7), PAH group (n=8), PAH+ RSD group(n=7). Pulmonary artery hypertension models were made by monocrotaline injection in PAH group and PAH+ RSD group, while bilateral renal artery sympathetic nerve were also ablated in PAH+ RSD group. Meanwhile, sham operation treatment were made in the control group and PAH group. The changes of blood pressure and cardiac indicies of ultrasound were observed before and after 8 weeks respectively. Then the left ventricular(LV) lateral strain, septal strain (IVS LS) and right ventricular(RV) strain were calculated. In the apical 4-chamber view, time from QRS onset to peak systolic strain in each the six segments of the LV and RV were measured and standard deviation of the time to peak longitudinal strain of six segments(LVTsl-6SD and RVTsl-6SD) were calculated. LV twist degree were obtained from LV rotation curve in basal and apical short-axis planes. Results After 8 weeks, there was no difference in the mean strain of LV lateral wall among the three groups, while the mean strain of RV lateral wall and septal were higher in PAH+ RSD group than the PAH group [(18.91±0.86)% % vs 16.34±1.36)%, P<0.001; (18.39±1.03)% vs (17.02±1.00)%, P<0.001, respectively]. Compared with PAH group, LVTsl-6SD and RVTsl-6SD of PAH+ RSD group decreased significantly [(25.45±3.59)ms vs (40.40±2.83)ms, P<0.001; (34.16±2.81)ms vs (51.98±3.64)ms, P<0.001, respectively]. The LV twist degree of PAH+ RSD group increased significantly[(10.47±0.73)° vs (8.46±1.06)°, P<0.001]. Conclusions RSD can reduce the influence of pulmonary artery hypertension on cardiac systolic function. Key words: Echocardiography; Hypertension, pulmonary; Renal sympathetic nerve; Catheter ablation; Ventricular function, left

Prolonged right ventricular ejection delay identifies high risk patients and gender differences in Brugada syndrome

Background and objectivesRight ventricular (RV) conduction delay has been suggested as an underlying pathophysiological mechanism in Brugada syndrome (BS). In this cross-sectional study we non-invasively assessed the value of echocardiographic markers reflecting ventricular ejection delay to further assess electromechanical abnormalities in BS and to identify patients at risk for life-threatening arrhythmic events. Furthermore, we sought to assess differences in ejection delays between genders because male BS patients demonstrate a more malignant clinical phenotype. Methods124 BS patients (57.3% males) and 62 controls (CTR) (48.4% males) were included. Using Tissue Velocity Imaging, the ejection delay, determined as the time from QRS onset to the onset of the sustained systolic contraction, was measured for both RV free wall (RVED) and lateral LV wall (LVED). From these parameters, the interventricular ejection delay between both walls (IVED) was calculated. ResultsBS patients had longer RVEDs and IVEDs compared to the CTR. BS patients with a previous history of syncope or spontaneous ventricular arrhythmia showed the longest RVEDs and IVEDs. Male BS patients demonstrated longer RVEDs and IVEDs than females. Male BS patients with malignant events had the longest delays. No significant differences regarding LVED were observed between BS patients and CTR. ConclusionsWe demonstrated that a previous history of malignant events was associated with longer RVEDs. Our findings supported the RV conduction delay mechanism behind BS and demonstrated for the first time that the predominant malignant male Brugada phenotype might also be the result of a more delayed RV conduction in males.

Septal and anterior reverse mismatch of myocardial perfusion and metabolism in patients with coronary artery disease and left bundle branch block.

The effects of left bundle branch block (LBBB) on left ventricular myocardial metabolism have not been well investigated. This study evaluated these effects in patients with coronary artery disease (CAD).Sixty-five CAD patients with complete LBBB (mean age, 61.8 ± 9.7 years) and 65 without LBBB (mean age, 59.9 ± 8.4 years) underwent single photon emission computed tomography, positron emission tomography, and contrast coronary angiography. The relationship between myocardial perfusion and metabolism and reverse mismatch score, and that between QRS length and reverse mismatch score and wall motion score were evaluated.The incidence of left ventricular septum and anterior wall reverse mismatching between the two groups was significantly different (P < 0.001 and P = 0.002, respectively). The incidences of normal myocardial perfusion and metabolism in the left ventricular lateral and inferior walls were also significantly different between the two groups (P < 0.001 and P < 0.001, respectively). The incidence of septal reverse mismatching in patients with mild to moderate perfusion was significantly higher among those with LBBB than among those without LBBB (P < 0.001). In CAD patients with LBBB, septal reverse mismatching was significantly more common among those with mild to moderate perfusion than among those with severe perfusion defects (P = 0.002). The correlation between the septal reverse mismatch score and QRS length was significant (P = 0.026).In patients with CAD and LBBB, septal and anterior reverse mismatching of myocardial perfusion and metabolism was frequently present; the septal reverse mismatch score negatively correlated with the QRS interval.

Vector flow mapping for assessing Beagle dogs′ left ventricular vortex in selective bi-polar single site cardiac pacing

Objective To investigate the changes of left ventricular(LV) vortex strength(VS) and distribution during selective cardiac pacing in a phases of cardiac cycle using vector flow mapping techniques, and associate with LV mechanical performance, so as to provide basic experimental database for optimizing the sites of the artificial cardiac pacing in clinic conditions. Methods Eight heathy open-chest Beagle dog models were employed for selective right ventricular apical(RVAP), left ventricular apical(LVAP) and lateral wall pacing(LVLP). The standard two-dimensional apical three views with color Doppler flow and dynamic two-dimensional images were acquired consecutively in three cardiac cycles for further off-line analysis, conventional parameters were measured at same time. Results Compared with baseline, LVSV, LVEF, LVCO and dp/dtmax were both reduced, and the parameters obtained leftside cardiac pacing were lower than that of right ventricular pacing (P<0.05), there′s no significant difference in E/Vp. The vortex pattern, distribution and vorticity at six typical phases induced by selective cardiac pacing were totally different from those at baseline with sinus rhythm, and leftside pacing were worsen than RVAP, the LVAP were most obvious. On multivariable regression analysis, the VS during ES(VSES) at baseline was independently related to late-diastolic VS and longitudinal strain (R2=0.63, P<0.001 and P=0.003, respectively). Conclusions The selective cardiac pacing could induce intracardiac vortex changes and differ from that at baseline, and the persistence of vortex from late diastole into ES is a haemodynamic measure of coupling between diastole and systole. Key words: Echocardiography; Ventricular function, left; Cardiac pacing, artificial; Vortex; Vector flow mapping

Left ventricular longitudinal rotation changes in primary hypertension patients with normal left ventricular ejection fraction detected by two-dimensional speckle tracking imaging.

In order to assess the left ventricular (LV) longitudinal rotation (LR) in primary hypertension (PH) patients with a normal LV ejection fraction. Conventional echocardiography was performed in 61 healthy subjects and 64 PH patients. The apical four-chamber views in these patients were acquired by GE-Vivid7 or E9, then the peak radial strain in the systolic period and the strain rate in systole, in early and late diastolic periods, were measured. Segmental LR and global LR were assessed by using two-dimensional speckle tracking imaging (2D-STI). The peak radial strain rate in the early diastolic period in PH patients was significantly lower than that in healthy subjects. The rotational degrees of the middle and base lateral, the apex and the middle septum walls in PH patients were significantly different from those of the healthy subjects. The healthy subjects had prominent counter-clockwise LR (0.29°±2.86°) and the PH patients had prominent clockwise LR (-2.13°±2.93°) in non-LV wall hypertrophy and (-2.43°±2.66°) in LV wall hypertrophy. The time delay between the LV lateral wall and the septum wall in PH patients correlated to the peak LR. We concluded that 2D-STI can assess the time delay between the LV lateral wall and the septum wall to the peak LR and clockwise LR in patients with PH, and prove that PH patients have a clockwise LR. By this, we conclude that in PH patients, the LV early systolic function have changed.

Global left ventricular relaxation: A novel tissue Doppler index of acute rejection in pediatric heart transplantation

Serial invasive cardiac catheterization with endomyocardial biopsies (EMBs) is the current standard of reference for evaluation after orthotopic heart transplant (OHTx). We developed a novel, non-invasive echocardiographic index of global left ventricular relaxation (LVRI) and assessed its sensitivity, specificity and predictive value for detecting rejection compared with EMB results in a prospective study conducted from September 2012 through May 2014. LVRI was calculated as the sum of diastolic tissue Doppler imaging (TDI) velocities (E') of the left ventricular lateral, septal and posterior walls divided by the percentage of left ventricular posterior wall (LVPW) thinning by M-mode. LVRI was measured in 47 OHTx patients and 50 patients with normal hearts. Of the 33 patients who underwent clinically indicated EMB, 22 patients had Grade 0R EMB, 6 had Grade 1R and 5 had Grade 2R to 3R biopsy results. Sensitivity, specificity and predictive value of LVRI for discriminating Grade 1R to 3R EMB were calculated. The LVRI was compared before and after OHTx rejection treatment and during the early and late post-transplant period. To characterize LVRI, 1-way analysis of variance was used to compare all groups, including non-OHTx patients. LVRI was lower in patients with Grade 0R EMBs compared with non-OHTx patients. Patients with Grade 1R to 3R EMBs had lower LVRI than those with Grade 0R EMBs. LVRI recovered after treatment for rejection. LVRI appeared to normalize between 40 and 90 days post-transplantation. After 90 days, sensitivity was 100% and specificity was 90.9% for detecting patients with Grade 1R to 3R EMBs using an LVRI of 0.8. LVRI, a novel, non-invasive TDI index of global left ventricular diastolic dysfunction, appears to be useful for detecting rejection in children beyond 3 months post-OHTx.

Prominent T wave in V2 with respect to V6 as a sign of lateral myocardial infarction

BackgroundIn the absence of confounding electrocardiographic features, a prominent R wave in leads V1–V2 reflects a lateral myocardial infarction (MI). We hypothesized that repolarization abnormalities in V1–V2 could also reflect a lateral MI. MethodsWe retrospectively selected a group of 57 patients with a recent or previous first Q-wave MI involving left ventricular (LV) inferior and/or lateral wall at contrast-enhanced cardiac magnetic resonance (CMR). The location and extent of the MI at CMR were compared with electrocardiographic features. ResultsThe infarction was located in the inferior wall in 12 patients (21%), in the lateral wall in 8 (14%), and in both walls in 37 patients (65%). Infarct size corresponded to 16.8 (SD 9.0%) of LV myocardium. Infarct extent in the inferior and lateral wall (8.3%, SD 7.2% vs. 8.4%, SD 7.5% of LV myocardium) did not differ significantly. Using multiple linear regression analysis, inferior Q-waves and inferior negative T waves were directly associated with infarct extent in the inferior wall (p=0.014 and p=0.010, respectively). A prominent R wave in V1 and a prominent anterior T wave (expressed by the T wave amplitude in V2 minus its amplitude in V6) were directly associated with MI extent in the lateral wall (p=0.008 and p=0.018), while inferior negative T waves were negatively associated (p=0.006). ConclusionsIn patients with MI of the inferior and/or lateral wall, a prominent T wave in V2 with respect to V6 reflects greater infarct extent in the lateral wall.

0408 : A prominent R wave in V1 but not in V2 is a specific sign of a large lateral infarction: Algerian study

In the absence of right ventricular hypertrophy or bundle-branch block, a prominent R wave in V1 or V2 is considered to reflect a lateral myocardial infarction. We investigated the differences in infarct location and size between patients with prominent R wave in V1 and those with prominent R wave in V2. We studied 50 patients with a previous first infarction involving left ventricular inferior and/or lateral wall at myocardial scintigraphy A prominent R wave in V1 was present in 8 patients (16%), in V2 in 23 (46%). At myocardial scintigraphy, the infarction involved the inferior wall in 11 patients (22%), the lateral wall in 6 (12%), and both walls in 33 patients (66%). The sensitivity of a prominent R wave in V1 in detecting a lateral infarction was low (17.9%), while the specificity was high (90.9%). The sensitivity and specificity of a prominent R wave in V2 were 46.2% and 54.5%, respectively. In patients with a prominent R wave in V1, infarct size and lateral extent were greater than in patients without this pattern (P<.005 and <.0.01 respectively). In patients with a prominent R wave in V2, infarct size, lateral extent were not different from patients without this pattern. Only a prominent R wave in V1 is a specific sign of large lateral infarction.