Basal Interventricular Septum Research Articles

Transverse false tendons in the left ventricular cavity are associated with early repolarization.

BackgroundLeft ventricular false tendons (LVFTs) are related to precordial murmurs, ventricular arrhythmias and some repolarization abnormalities. Early repolarization (ER) is a specific type of repolarization abnormality.ObjectiveThe aim of the present study was to investigate the relationship between LVFTs and ER.MethodsThis study retrospectively included 99 consecutive healthy subjects and 33 patients with ER. Early repolarization was defined as an elevation of the QRS-ST junction of >0.1 mV from baseline in at least 2 inferior or lateral leads, manifested as QRS slurring or notching. Each participant was examined using echocardiography with second harmonic imaging, and the attachments of the LVFTs were recorded.ResultsA total of 93 LVFTs were present in 82 (83%) of the 99 healthy subjects. Of these 93 LVFTs, the majority (79/93, or 84.9%) were longitudinal-type LVFTs, which originated from the basal interventricular septum (IVS) and progressed toward the apical segment of the left ventricular free wall. There were significant differences in the positioning of the LVFTs between the ER patients and control (P < 0.0001). LVFTs between mid-IVS to the middle of the LV free wall were found more common in patients with ER compared with control subjects (47.5% vs. 6.5%, P < 0.0001). In the ER group, LVFTs between the basal IVS to the apical segment of LV free wall were only identified in 21% of the LVFTs, compared to a value of 84.9% for the control group (P < 0.0001). The distribution of LVFT trends in the ER group was also significantly different from that in the control group (P < 0.05).ConclusionsLVFTs are commonly visualized using echocardiography. An LVFT from the basal IVS to the apical segment of the left ventricular free wall may be a normal anatomical structure in the left ventricular cavity. On the contrary, transverse false tendons in the left ventricular cavity may be associated with ER.

Detection of significant stenosis in the Left Anterior Descending Artery by ‘Virtual Myocardial Perfusion’ Bolus Tracking, 320 Slice Computed Tomography

PurposeWe used bolus-tracking CT-images, which are usually used only to detect contrast-material in target organs for optimal-starting of acquisition, as virtual first pass myocardial perfusion images. MethodsRetrospective-analysis of 14 patients (10 male, 63±10years) diagnosed with ≥75% stenosis confined to left-anterior-descending-artery (LAD) (7 patients, Group-1) or insignificant stenosis of any coronary artery (7 patients Group-2) diagnosed using invasive-coronary-angiograms (ICA) and enhanced 320-slice-CT within 3-months and without incident between examinations. Bolus-tracking CT-images were acquired at mid-level left-ventricle (LV) until CT-attenuation of descending-aorta increased to 200HU. We measured CT-attenuation (HU) in the LV anterior-wall (AW), the basal inter-ventricular-septum (BIVS), and LV basal lateral-wall (BLW) in end-systole using both bolus-tracking images and routine, enhanced, early-phase CT-images. ResultsIn the bolus-tracking images, the Group-1 LV AW, BIVS, BLW CT-attenuation and ratio of LV AW CT attenuation to the average of BIVS and BLW were 36±7HU, 62±11HU, 58±25HU, and 0.6±0.1 respectively. In Group-2, they were 53±14HU, 56±9HU, 54±15HU, and 1.0±0.3 respectively. LV AW CT attenuation and the ratio of LV AW CT values to the average of BIVS and BLW, were significantly lower in Group-1 (both P<0.05). These values were not significant using routine, enhanced, early-phase CT-images. ConclusionsBolus-tracking CT-images may be useful to detect the LAD-confined stenosis that cannot be detected using routine, enhanced, early-phase CT-images. This can be achieved by measuring the local-reduction in CT-attenuation of the LV AW compared with the average of those of the BIVS and BLW and without the need for drugs, exercise or additional radiation-exposure.

Normal and shear strains of the left ventricle in healthy human subjects measured by two-dimensional speckle tracking echocardiography

BackgroundAnimal studies have shown that shear deformation of myocardial sheets in transmural planes of left ventricular (LV) wall is an important mechanism for systolic wall thickening, and normal and shear strains of the LV free wall differ from those of the interventricular septum (IVS). We sought to test whether these also hold for human hearts.MethodsThirty healthy volunteers (male 23 and female 7, aged 34 ± 6 years) from Outpatient Department of the University of Tokyo Hospital were included. Echocardiographic images were obtained in the left decubitus position using a commercially available system (Aloka SSD-6500, Japan) equipped with a 3.5-MHz transducer. The ECG was recorded simultaneously. The peak systolic radial normal strain (length change), shear strain (angle change) and time to peak systolic radial normal strain were obtained non-invasively by two-dimensional speckle tracking echocardiography.ResultsThe peak systolic radial normal strain in both IVS and LV posterior wall (LVPW) showed a trend to increase progressively from the apical level to the basal level, especially at short axis views, and the peak systolic radial normal strain of LVPW was significantly greater than that of IVS at all three levels. The time to peak systolic radial normal strain was the shortest at the basal IVS, and increased progressively from the base to the apical IVS. It gradually increased from the apical to the basal LVPW in sequence, especially at short axis views. The peak of radial normal strain of LVPW occurred much later than the peak of IVS at all three levels. For IVS, the shear deformation was clockwise at basal level, and counterclockwise at mid and apical levels in LV long-axis view. For LVPW, the shear deformations were all counterclockwise in LV long-axis view and increased slightly from base to the apex. LVPW showed larger shear strains than IVS at all three levels. Bland-Altman analysis shows very good agreement between measurements taken by the same observer and by two independent observers.Conclusion“Myocardial sheets” theory also holds true for intact human LV. Moreover, dyssynchrony exists even in healthy human subjects, which should be considered when evaluating the diseased hearts.

Diffuse myocardial fibrosis following tetralogy of Fallot repair: a T1 mapping cardiac magnetic resonance study

Adverse ventricular remodeling after tetralogy of Fallot (TOF) repair is associated with diffuse myocardial fibrosis. The goal of this study was to measure post-contrast myocardial T1 in pediatric patients after TOF repair as surrogates of myocardial fibrosis. Children after TOF repair who underwent cardiac magnetic resonance imaging with T1 mapping using the modified look-locker inversion recovery (MOLLI) sequence were included. In addition to routine volumetric and flow data, we measured post-contrast T1 values of the basal interventricular septum, the left ventricular (LV) lateral wall, and the inferior and anterior walls of the right ventricle (RV). Results were compared to data from age-matched healthy controls. The scans of 18 children who had undergone TOF repair and 12 healthy children were included. Post-contrast T1 values of the left ventricular lateral wall (443 ± 54 vs. 510 ± 77 ms, P = 0.0168) and of the right ventricular anterior wall (333 ± 62 vs. 392 ± 72 ms, P = 0.0423) were significantly shorter in children with TOF repair than in controls, suggesting a higher degree of fibrosis. In children with TOF repair, but not in controls, post-contrast T1 values were shorter in the right ventricle than the left ventricle and shorter in the anterior wall of the right ventricle than in the inferior segments. In the TOF group, post-contrast T1 values of the RV anterior wall correlated with the RV end-systolic volume indexed to body surface area (r = 0.54; r(2) = 0.30; P = 0.0238). In children who underwent tetralogy of Fallot repair the myocardium of both ventricles appears to bear an abnormally high fibrosis burden.

TCT-124 A novel appliance for transcatheter mitral cerclage annuloplasty

Mitral cerclage annuloplasty is a transcatheter coronary sinus annuloplasty that establishes circumferential tension around the mitral annulus by traversing the basal interventricular septum between the great cardiac vein and the right ventricular outflow tract. We have developed a novel implant to

Longitudinal follow-up of ventricular performance in healthy neonates

BackgroundSpecific follow-up of newly introduced echocardiographic parameters in healthy neonates and infants is limited. AimTo prospectively describe follow-up of left ventricular (LV) tissue Doppler imaging (TDI) and speckle tracking strain parameters in healthy subjects up to two months after birth. DesignThis is a longitudinal follow-up study. SubjectsTwenty-eight (10 male) healthy newborns were included and underwent transthoracic echocardiography 1–3days, 3weeks and 6–7weeks after birth. Outcome measuresIn each echocardiogram, parameters describing cardiac growth, including LV mass (LVM), were assessed. Additionally, TDI derived peak systolic velocity (S′) and peak early (E′) and late (A′) diastolic velocities were assessed in the basal LV free wall and interventricular septum (IVS). Finally LV longitudinal, radial and circumferential global peak strain parameters were assessed using speckle tracking strain imaging. ResultsLVM significantly increased during follow-up (7.6±2.4 versus 12.4±3.2g, p=0.002). Similarly at 1–3days versus 6–7weeks after birth, an increase in LV and IVS systolic (LV S′ 4.1±1.5 versus 6.3±1.5cm/s, p=0.001; IVS S′ 3.6±0.9 versus 6.4±1.3cm/s, p<0.001) and diastolic (LV E′ 6.1±2.2 versus 9.7±2.9cm/s, p=0.002; IVS E′ 5.1±1.4 versus 10.7±3.3cm/s, p<0.001) TDI parameters was observed. In contrast, global peak longitudinal, radial and circumferential strain parameters did not significantly change during follow-up. ConclusionsA significant increase in LV systolic and diastolic TDI parameters was observed up to two months after birth. Yet this increase may be (cardiac) growth-dependent. No significant changes were observed in speckle tracking strain derived global peak strain parameters; this may render the technique particularly valuable in evaluation of LV systolic performance during periods of significant growth, such as the neonatal period.

160 DIFFUSE FIBROSIS IN ALSTRöM SYNDROME: A MARKER OF DISEASE PROGRESSION

Background Alstrom syndrome (ALMS) is a rare autosomal recessive genetic disorder with progressive multi-system involvement including; endocrine disarray, sensorineural deficit, cardiac, renal, and hepatic abnormalities. Idiopathic dilated cardiomyopathy (CM) is a major cause of morbidity and mortality. It is observed acutely in infancy in approximately 45% of individuals with high rates of recurrence and new cases in adulthood. Myocardial fibrosis has been demonstrated at post-mortem and on MRI with patchy diffuse late gadolinium enhancement (LE) in an older cohort of ALMS patients. We hypothesise that subclinical diffuse fibrosis in young patients with ALMS precedes any change in conventional parameters of ventricular function or overt scarring on LE. Methods Ten patients with ALMS (mean age 30±11 years, 70% male, 24 h ABPM 135±13/84±9 mm Hg) were compared to 10 newly diagnosed borderline hypertensive patients (mean age 42 years, 70% male, 24 h ABPM 134±8/84±8 mm Hg) and 10 gender matched healthy volunteers. All subjects underwent cardiac MRI (1.5T). Myocardial extracellular volume (ECV) was assessed using T1-mapping pre and 15 min post gadolinium (0.1 mmol/kg) using a modified look-locker inversion recovery sequence (MOLLI). Late gadolinium images were acquired 5–7 min after contrast. Myocardial T1 was assessed by manual contouring of the basal and mid interventricular septum, avoiding areas of LE from a four chamber view. Results Females in all three groups had significantly increased septal myocardial ECV compared with males (0.29±0.03 vs 0.25±0.03, p Conclusions Patients with ALMS have increased septal myocardial fibrosis and reduced longitudinal systolic function which appears independent of blood pressure and left ventricular hypertrophy. Monitoring left ventricular ECV as an imaging biomarker may be a target for early modification of pharmacological therapy in this cohort at high cardiovascular risk. Funding National Commissioning Group.

Third-Degree Atrioventricular Block in an Adult With a Giant Cardiac Fibroma

A 48-year-old man was admitted with exertional dyspnea. An ECG on admission revealed third-degree atrioventricular block (Figure 1). Transthoracic echocardiography demonstrated a giant mass, 6.4×6.5×7 cm, located in the basal interventricular septum (Figure 2A and 2B and Movie I in the online-only Data Supplement). The left ventricular outlet tract was mildly obstructed (Figure 2C and 2D and Movie II in the online-only Data Supplement). Cardiac magnetic resonance imaging (MRI) was recommended. A huge mass with well-defined borders was identified in the basal posterior interventricular septum (6×7 cm), which was low signal on a T1-weighted image, showed no signal suppression on a fat saturation sequence (Figure 3A and 3B and Movies III and IV in the online-only Data Supplement), and demonstrated low signal on a T2-weighted image (Figure 3C). There was no perfusion within the mass on first-pass gadolinium perfusion images (Figure 3D and Movie V in the online-only Data …

Myocardial function in children after fetal chemotherapy exposure. A tissue Doppler and myocardial deformation imaging study

Chemotherapy and particularly anthracycline exposure are associated with acute and chronic cardiotoxicity. Few data exist on the effect of cardiac function after in utero exposure to maternal chemotherapy. Our recently published multicenter prospective study showed no significant changes in systolic function using conventional echocardiographic parameters. The purpose of this study was to further investigate whether early functional changes can be detected using tissue Doppler imaging (TDI) and two-dimensional (2D) speckle tracking echocardiography (STE). Sixty-two children (median/range age 1.7 (1-9.8) years) exposed to chemotherapy during fetal life were enrolled and compared to 62 age- and gender-matched controls. TDI velocities were measured at the basal interventricular septum (IVS) and right and left ventricular (LV) free walls. LV global longitudinal and circumferential systolic strains were derived using 2D STE. We found small but significant differences between the groups (patients versus controls) in LV fractional shortening [35 (29-46)% versus 39 (28-53)%, p < 0.001], LV ejection fraction [66 (57-79)% versus 70 (57-83)%, p < 0.001], LV posterior wall thickness z score [-0.15 (-2.32-1.81) versus -0.10 (-1.9-2.0), p < 0.001], and IVS thickness z score [-1.06 (-2.6-1.3) versus -0.5 (-2.1-1.7), p < 0.001]. No significant differences in TDI velocities or LV global strains were observed. Within the patient group, the cardiac functional parameters did not correlate to the number of cycles of anthracycline or the cumulative anthracycline dose. Children exposed to fetal chemotherapy have a lower normal fractional shortening and mildly lower left ventricular wall thickness. Tissue Doppler and strain measurements are within normal range and not statistically different from normal controls. The long-term implications of these findings will be further studied in this prospective cohort study.

136 3-Dimensional Late Gadolinium Enhancement Scar Imaging For Surgically Corrected Tetrology Of Fallot: Clinical Feasibility Of Scar Segmentation

Surgical correction of Tetrology of Fallot (TOF) necessitates varying degrees of “scar” within the right ventricular (RV) infundibulum and basal inter-ventricular septum. The visual scoring of scar by late gadolinium enhancement (LGE) MRI is associated with RV dysfunction and may be the primary substrate for ventricular arrhythmia. However, its spatial characterization on 2D LGE imaging is challenging due to complex and thin architecture. In this study we describe the first clinical experience of high-resolution 3D LGE imaging for the characterization and quantification of scar in this population.

Longitudinal strain curves in the RV free wall differ in morphology in patients with pulmonary hypertension compared to controls

BackgroundPrevious studies using speckle tracking-derived strain for quantification of right ventricular (RV) function in pulmonary hypertension (PHT) have focused on the magnitude of global and regional peak longitudinal systolic strains (PLSS) and systolic strain-related indices of dyssynchrony. The aim of our study was to investigate the pattern of RV contraction and relaxation with the use of the contour and timing of strain and velocity curves in PHT. MethodsThe study population consisted of thirty‐seven patients with PHT (45±18years, 16 women) and thirty‐seven controls. A complete two-dimensional echo with speckle-tracking-derived longitudinal strain of the basal RV free wall and interventricular septum (IVS) was performed and the cycle length-corrected time to PLSS (SST) and time from PLSS to 50% of PLSS (systolic strain half time—SSHT) in both regions were calculated. ResultsPatients with PHT had significantly reduced PLSS (−24.9±2.0% vs −43.2±3.0%, p<0.001) and increased SST (0.47±0.02 vs 0.39±0.02, p=0.043) and SSHT (0.22±0.02 vs 0.16±0.02, p=0.047) in the basal RV free wall compared to controls. Furthermore, peak systolic velocities were observed earlier in the cardiac cycle in both regions in patients with PHT compared to controls. ConclusionsLongitudinal strain curves in the RV free wall reach peak values later in the cardiac cycle and return slower towards the baseline in PHT. Furthermore, peak systolic velocities are observed earlier in the cardiac cycle in both the basal RV free wall and the basal IVS. The above observations effectively illustrate changes in patterns of RV contraction and relaxation caused by PHT.

Bipolar Ablation of Ventricular Tachycardia in a Patient After Atrial Switch Operation for Dextro-Transposition of the Great Arteries

A 39-year-old man with atrial switch repair (Mustard baffle) and transpulmonary resection of infundibular muscle for dextro-transposition of the great arteries and subpulmonary stenosis was referred for ablation of a drug-refractory monomorphic ventricular tachycardia (VT). Before the ablation, the patient underwent multidetector CT to detect anomalous coronary anatomy (Figure 1A–1C) and contrast-enhanced MRI (CE-MRI) to determine the extent of scar after surgical resection. CE-MRI showed late enhancement in the basal interventricular septum extending toward aortic sinus 2 (origin of the circumflex artery) (Figure 1D and 1E). During the ablation procedure, both multidetector CT and CE-MRI-derived images were integrated with the electroanatomical maps. VT was induced, and diastolic activity could be recorded at the aortic sinus 2 and at the opposing site in the right ventricle (RV). There was no capture when high-output pacing at these sites was performed to entrain the VT. Irrigated-tip radiofrequency (RF) delivery resulted in slowing of the VT when applied from the aortic sinus site (up to 40 W; flow rate, 20 mL/min) and consecutive late termination when RF was delivered from the RV site (up to 50 W; flow rate, 30 mL/min). Figure 1. MDCT and CE-MRI images. A , The RV is connected to the AO. The LAD and the RCA have a common ostium in sinus 1, whereas the CX has a separate ostium in sinus 2. B , The PVs are connected to the RA, and the VCS to the Mustard baffle, directing blood to the LV. C , The poststenotic dilation of the PT is clearly visible. The infundibular septum is indicated by white arrowheads. D and E , The 3D reconstruction of the CE-MRI-derived scar, with red indicating core scar and yellow, border zone scar. Note the potential anatomic isthmus bordered by aortic sinus 2 and a scar in …

In Memoriam: Thomas N. James, MD

diography (Definity, Lantheus Medical Imaging, North Billerica, MA, USA) demonstrated reduced perfusion of the basal inferior septum with borderline left ventricular function. Throughout the remainder of his hospital stay, the patient displayed no evidence of clinical PVCs or VT. He was discharged home 2 days postprocedure. Catheter-based ablation of recurrent sustained monomorphic VT is an important therapeutic option for patients with frequent, drug-refractory ICD shocks. It is not uncommon for VT to arise from the basal interventricular septum, particularly in patients with nonischemic cardiomyopathy. In these cases, radiofrequency ablation may fail, and transcoronary ethanol ablation is an option. To our knowldge, this is the first report of successful transcoronary thanol ablation for VT via an anomalous septal perforating rtery arising from the right sinus of Valsalva. Anomalous

Is multidetector computed tomography a suitable alternative to MR imaging for the assessment of myocardial necrosis after alcohol septal ablation?

BackgroundTo compare magnetic resonance (MR) imaging and multidetector computed tomography (MDCT) for the assessment of myocardial infarction (MI) after alcohol septal ablation (ASA). MethodsTen patients (mean age, 60 years±16) were examined with both MDCT and 1.5-T MR imaging performed 10 minutes after injection, within 3 days after ASA. Half of them had a temporary pacemaker (PM) during MDCT examination. Global image quality (IQ) and localization of MI were noticed on both MDCT and MR images. Volumes of MI, contrast-to-noise ratios (CNR) and signal-to-noise ratios (SNR) were also calculated. ASA effectiveness was evaluated by echocardiography immediately and 3 months after procedure. ResultsGlobal IQ was considered adequate for both procedures. In 8 patients, MI reached the basal part of the septum on both MDCT and MR images. The 2 remaining patients exhibited sparing of the basal septum on MDCT and MR images. Volumes of MI were within the same range with the 2 techniques (MDCT: 22.1±8.8 mL; MR imaging: 23.8±9.4 mL) and correlated well each other (R2=0.85, p<0.002). The 2 patients with sparing of the basal interventricular septum had persistent gradient on echocardiography 3 months after ASA, suggesting failure of the procedure. The volumes of MI didn't correlate with the reduction of pressure gradient on echocardiography 3 months after ASA (R2=0.02, p<0.05). ConclusionsEvaluation of post ASA MI is feasible with MDCT by comparison with MR imaging. MDCT might serve as an alternative imaging method in case of PM implantation.

Follow-Up by Cardiac Magnetic Resonance Imaging in Patients With Hypertrophic Cardiomyopathy Who Underwent Percutaneous Ventricular Septal Ablation

To evaluate myocardial infarction and describe the early to mid-term changes induced by percutaneous ventricular septal ablation (PVSA) in symptomatic patients with hypertrophic cardiomyopathy using cardiac magnetic resonance imaging. Cardiac magnetic resonance imaging was performed before and 1 week and 1 year after PVSA in 52 patients. The relation between the infarction size and other factors was determined. At 1 week after PVSA, regional hyperenhancement was visualized in the basal interventricular septum in all patients. The mean infarction size was 29.5 ± 15.9 g. The infarction size correlated well with the ethanol volume. The left ventricular myocardial mass decreased significantly from 196.1 ± 65.9 g at baseline to 183.4 ± 63.6 g 1 week after PVSA (p <0.001) and 164.1 ± 60.9 g within the 1-year follow-up period (p <0.001). In conclusion, cardiac magnetic resonance imaging allowed a detailed evaluation of the size and location of septal myocardial infarction induced by PVSA. The left ventricular myocardial mass decreased significantly during the follow-up period.

Two-Dimensional Speckle Strain and Dyssynchrony in Single Right Ventricles Versus Normal Right Ventricles

Patients with single-right ventricle (RV) physiology are at increased risk for myocardial dysfunction and mechanical dyssynchrony. Newer echocardiographic modalities may be better able to quantitate right ventricular function in this unique population. The aim of this study was to use two-dimensional speckle analysis of strain and strain rate to quantify systolic function and dyssynchrony in single-RV post-Fontan patients and compare them with values for controls. Patients with single RV who underwent Fontan palliation and patients with normal biventricular anatomy were studied. Two-dimensional speckle echocardiography was used to measure strain, strain rate, time to peak, and longitudinal displacement in a 6-segment model of the RV. Independent t tests were used to compare group means. P values < .05 were considered significant. Thirteen patients were studied in each group. There was no significant difference in age between single-RV patients and controls (6.60 +/- 2.07 vs 5.75 +/- 1.83 years, respectively). Single-RV strain values were significantly lower in all 6 segments compared with values in controls (basal interventricular septum [IVS], -14.28 +/- 7.78% vs -22.00 +/- 2.36%; mid IVS, -17.70 +/- 4.54% vs -22.99 +/- 2.71%; apical IVS, -19.46 +/- 4.97% vs -25.42 +/- 4.06%; basal RV, -22.40 +/- 5.7% vs -41.42 +/- 5.42%; mid RV, -21.20 +/- 3.21% vs -39.67 +/- 6.04%; apical RV, -20.70 +/- 4.90% vs -33.68 +/- 3.90%). Systolic strain rate and longitudinal displacement were also lower in the free wall and apical IVS in single-RV patients compared with controls. The modified Yu index for strain time to peak was longer in the single-RV patients (43.16 +/- 13.63 vs 21.72 +/- 7.25 ms). Significant differences in strain analysis between single-RV patients and patients with biventricular physiology exist at a relatively young age. Future studies are needed to determine the clinical significance of these differences.

Role of cardiac computed tomography in planning and evaluating percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy

A 72-year-old woman with hypertrophic obstructive cardiomyopathy underwent coronary computed tomography (CT) angiography that showed perfusion of the hypertrophied interventricular septum by the first septal artery. One month after percutaneous transluminal septal myocardial ablation, repeat CT perfusion imaging identified a transmural myocardial infarction in the basal hypertrophic interventricular septum which clinically correlated with a reduction in left ventricular outflow tract obstruction.

Hypertrophic Cardiomyopathy: The Early Years

Hypertrophic obstructive cardiomyopathy (HOCM) has four major features: (1) severe left ventricular hypertrophy, often most prominent in the basal interventricular septum; (2) frequent familial occurrence with autosomal dominant transmission; (3) occurrence of sudden cardiac death that is usually considered to be due to ventricular fibrillation; and (4) presence of hemodynamic evidence of labile intraventricular obstruction. The key papers describing the recognition of each of these features, as well as of various combinations of them, are reviewed in this paper. Particular attention is focused on the very frequent finding of marked lability of intraventricular obstruction. The recognition of this fourth and last major feature in 1959 makes 2009 the golden anniversary year marking completion of the description of the major features of HOCM.

Cardiac sarcoidosis complicated with atrioventricular block and wall thinning, edema and fibrosis in left ventricle: Confirmed recovery to normal sinus rhythm and visualization of edema improvement by administration of predonisolone

A 65 year-old female had a node of some kind in her right leg five years ago and was diagnosed with sarcoidosis by gallium scintigraphy. Serum angiotension-converting enzyme levels had gradually increased, and three months ago she felt palpitations and dizziness when standing. On electrocardiogram, 2:1 atrioventricular (AV) block was observed. On transthoracic echocardiogram, the basal portion of the interventricular septum (IVS) revealed wall thinning with dyskinetic motion and lack of systolic thickening, and low attenuation. The basal portion of the left ventricular (LV) posterior inferior wall revealed mild wall thickening with low attenuation. Enhanced multislice-CT revealed a thickened LV posterior wall and thinned basal portion of IVS with interstitial change suggesting presence of fibrosis or edema. Late enhancement was also observed in the basal portion of the LV posterior inferior wall and basal IVS in T1 weighted magnetic resonance imaging (MRI); in addition, an area, the center of which indicated low attenuation surrounded by high attenuation, was observed in the basal portion of the LV posterior inferior wall in T2 weighted MRI. Positron emission tomography (PET) imaging using F-18 fluoro-deoxyglucose with the subject fasted for 6 h beforehand, revealed strong uptake in the basal portion of IVS and a thickened LV posterior wall, suggesting the presence of inflammation. Administration of predonisolone was started before pacemaker implantation and clinical symptoms immediately disappeared; in addition AV block recovered to normal sinus rhythm. On a repeat MRI performed four months later, the late enhancement in T1 weighted MRI and the high attenuation surrounding low attenuation in the basal portion of the LV posterior inferior wall in T2 weighted MRI both disappeared, and we confirmed that temporary edema had also disappeared.

Reverse left septal activation during intermittent left bundle-branch block: Indirect proof for concealed retrograde left bundle-branch activation

Concealed retrograde activation of bundle branch has been often proposed for explaining the persistence of functional rate-dependent bundle-branch block, but direct proof of such a mechanism in man has rarely been demonstrated. We report intracardiac recordings compatible with a reversal of activation of the left basal interventricular septum during intermittent left bundle-branch block. In our case, however, retrograde activation into the left bundle-branch cannot be recordable, probably due to the concealment within the muscular septal activation, even if this may explain the perpetuation of bundle-branch block according to the linking phenomenon.