Incremental value of tricuspid annular enlargement to progressive tricuspid regurgitation in patients with longstanding persistent atrial fibrillation.

Tricuspid annular enlargement in patients with atrial fibrillation (AF) can induce tricuspid regurgitation (TR). However, risk factors associated with TR progression in patients with AF have not been defined. This study aimed to clarify an association between tricuspid annular diameter (TAD) and TR progression in patients with longstanding persistent AF. We retrospectively analyzed data from 228 patients who had longstanding persistent AF for > 1 year and mild or less TR on baseline echocardiograms. We defined significant TR as moderate or greater TR, graded according to the jet area and vena contracta. The optimal cut-off value of the TAD index (TADI), based on body surface area for predicting progression to significant TR, was estimated using receiver operating characteristic (ROC) curves. The independence and incremental value of the TADI were evaluated using multivariate Cox proportional hazard regression analysis and likelihood ratio tests. Over a median follow-up of 3.7 years, 55 (24.1%) patients developed significant TR. The optimal cut-off value of 21.1 mm/m2 for the TADI at baseline and ROC curves predicted TR progression with 70.4% sensitivity and 86% specificity. Furthermore, TADI was an independent predictor of TR progression (hazard ratio, 1.32; 95% confidence interval, 1.17-1.49, P < 0.001) and had a significant incremental value that exceeded that of models constructed using clinical parameters. In conclusion, TADI was significantly associated with TR progression and was an independent predictor of TR progression in longstanding persistent AF.

Premature atrial contraction immediately after catheter ablation was associated with late recurrence of atrial fibrillation.

BACKGROUND: Although premature atrial contractions (PACs) just after catheter ablation (CA) for atrial fibrillation (AF) are common, their clinical significance is uncertain. This study aimed to evaluate whether the PAC burden after an initial CA for AF was associated with late recurrence. METHODS: We enrolled 346 patients with AF (median age, 65 years; 30% female; 57% with paroxysmal AF) who underwent an initial radiofrequency CA and a 24-h Holter monitoring the day after the procedure. PAC was defined as supraventricular complexes occurring ≥30% earlier than expected compared with a previous RR interval, and the number of PAC/24 h during post-procedural Holter monitoring was analyzed. RESULTS: AF recurred in 106 patients (31%) during a median follow-up of 19 months. These patients had significantly more PAC/24 h than those without (median [interquartile range], 891 [316-4351] beats vs. 409 [162-1,303] beats; p < 0.01). The number of PACs was independently associated with AF recurrence after adjustment for clinical parameters and left atrial (LA) enlargement. Receiver operating characteristic (ROC) curve analysis revealed that 1431 PAC/24 h was the optimal cut-off value for predicting AF recurrence. Adding the PAC/24 h to the prediction model with LA diameter appeared to correctly reclassify patients who were thought to be at high risk for AF recurrence into the low-risk group and vice versa. CONCLUSIONS: The number of PACs was an independent risk factor for AF recurrence. A 24-h Holter recording the day after an initial CA is a simple and beneficial tool for the risk stratification of AF recurrence.

Left ventricular longitudinal strain is a major determinant of CT-derived three-dimensional maximum principal strain: comparison with two-dimensional speckle tracking echocardiography.

Computed tomography (CT)-derived three-dimensional maximum principal strain (MP-strain) can provide incremental value to coronary CT angiography for cardiac dysfunction assessment with high diagnostic performance in patients with myocardial infarction. Global longitudinal strain (GLS) measured using two-dimensional speckle tracking echocardiography (2D-STE) is more sensitive than left ventricular ejection fraction (LVEF) for detecting early myocardial dysfunction. We aimed to compare CT-derived MP-strain with each of 2D-STE-derived strains (i.e., longitudinal, circumferential, and radial strains), and identify the major determinants of CT-derived MP-strain among 2D-STE-derived strains. We studied 51 patients who underwent cardiac CT and echocardiography. CT images were reconstructed at every 5% (0-95%) of the RR interval. A dedicated workstation was used to analyze CT-derived MP-strain on the 16-segment model. We calculated CT-derived global MP-strain with all the 16 segments on a per patient basis. Pearson's test was used to assess correlations between CT-derived MP-strain and STE-strain at global and segmental levels. The intra-class correlation coefficient for interobserver agreement for CT-derived global MP-strain was 0.98 (95% confidence interval 0.96-0.99). The low-CT-derived global MP-strain group (≤ 0.43) had more patients with LV dysfunction than the high-CT-derived global MP-strain group (> 0.43). CT-derived global MP-strain was associated with STE-GLS (r = 0.738, P < 0.001), global circumferential strain (r = 0.646, P < 0.001), and global radial strain (r = 0.432, P = 0.001). In multivariate analysis, STE-GLS had the strongest association to CT-derived global MP-strain among three directional STE-strains and LVEF by echocardiography (standardized coefficient = - 0.527, P < 0.001). STE-GLS is a major determinant of CT-derived global MP-strain. CT-derived MP-strain may enhance the value of coronary CT angiography by adding functional information to CT-derived LVEF.

Cardiac amyloidosis screening using a relative apical sparing pattern in patients with left ventricular hypertrophy.

BACKGROUND: Cardiac amyloidosis (CA) mimics left ventricular hypertrophy (LVH). It is treatable, but its prognosis is poor. A simple screening tool for CA would be valuable. CA is more precisely diagnosed with echocardiographic deformation parameters (e.g., relative apical sparing pattern [RASP]) than with conventional parameters. We aimed to 1) investigate incremental benefits of echocardiographic deformation parameters over established parameters for CA screening; 2) determine the resultant risk score for CA screening; and 3) externally validate the score in LVH patients. METHODS: We retrospectively studied 295 consecutive non-ischemic LVH patients who underwent detailed diagnostic tests. CA was diagnosed with biopsy or 99mTc-PYP scintigraphy. The base model comprised age (≥65 years [men], ≥70 years [women]), low voltage on the electrocardiogram, and posterior wall thickness ≥ 14 mm in reference to the literature. The incremental benefit of each binarized echocardiographic parameter over the base model was assessed using receiver operating characteristic curve analysis and comparisons of the area under the curve (AUC). RESULTS: Fifty-four (18%) patients had CA. RASP showed the most incremental benefit for CA screening over the base model. After conducting multiple logistic regression analysis for CA screening using four variables (RASP and base model components), a score was determined (range, 0-4 points). The score demonstrated adequate discrimination ability for CA (AUC = 0.86). This result was confirmed in another validation cohort (178 patients, AUC = 0.88). CONCLUSIONS: We developed a score incorporating RASP for CA screening. This score is potentially useful in the risk stratification and management of LVH patients.

Atrial tachycardia with multiple reconductions across the surgical incision.

Incisional atrial tachycardia (AT) with multiple penetrating points on one surgical incision has not been reported yet. We present a case of incisional AT following mitral valve annuloplasty with a superior transseptal approach, in which two reconduction sites were parts of the reentrant circuit. Radiofrequency ablation at the reconduction site successfully terminated the tachycardia. A total of four penetrating points were found on the incision line, and radiofrequency ablation at these sites was completed. Detailed mapping of possible reconduction sites along the incision line should be performed to avoid further instances of AT following open heart surgery.

Characteristics of the left ventricular three-dimensional maximum principal strain using cardiac computed tomography: reference values from subjects with normal cardiac function.

OBJECTIVES: This study evaluated the characteristics of left ventricular maximum principal strain (LV-MPS) using cardiac CT in subjects with normal LV function. METHODS: Of 973 subjects who underwent retrospective electrocardiogram-gated cardiac CT using a third-generation dual-source CT without beta-blocker administration, 31 subjects with preserved LV ejection fraction ≥ 55% assessed by echocardiography without coronary artery stenosis and cardiac pathology were retrospectively identified. CT images were reconstructed every 5% (0-95%) of the RR interval. LV-MPS and the time to peak (TTP) were analyzed using the 16-segment model and compared among three levels (base, mid, and apex) and among four regions (anterior, septum, inferior, and lateral) using the Steel-Dwass test. The intra- and inter-observer reproducibilities for LV-MPS were calculated using intraclass correlation coefficients (ICCs). RESULTS: The intra- and inter-observer ICCs (95% confidence interval) for peak LV-MPS were 0.96 (0.94-0.97) and 0.94 (0.92-0.96), respectively. The global peak LV-MPS (median, inter-quantile range) was 0.59 (0.55-0.72). The regional LV-MPS significantly increased in the order of the basal (0.54, 0.49-0.59), mid-LV (0.57, 0.53-0.65), and apex (0.68, 0.60-0.84) (p < 0.05, in each), and was significantly higher in the lateral wall (0.66, 0.60-0.77), while that in the septal region (0.47, 0.44-0.54) was the lowest among the four LV regions (all p < 0.05). No significant difference in TTP was seen among the myocardial levels and regions. CONCLUSION: CT-derived LV-MPS is reproducible and quantitatively represents synchronized myocardial contraction with heterogeneous values in subjects with normal LV function. KEY POINTS: • CT-derived left ventricular maximum principal strain analysis allows highly reproducible quantitative assessments of left ventricular myocardial contraction. • In subjects with normal cardiac function, the peak value of CT-derived left ventricular maximum principal strain is the highest in the apical level and in the lateral wall and the lowest in the septum. • The regional peak left ventricular maximum principal strain shows intra-ventricular heterogeneity on a per-patient basis, but myocardial contraction is globally synchronized in subjects with normal cardiac function seen on cardiac CT.

Semiquantitative assessment of the relative apical sparing pattern of longitudinal strain for cardiac amyloidosis identification.

BACKGROUNDS: The relative apical sparing pattern (RASP) of left ventricular (LV) longitudinal strain (LS) is frequently associated with cardiac amyloidosis (CA). However, the visual assessment of RASP is inconsistent, and the quantitative assessment of RASP is time-consuming. This study aimed to compare assessments of RASP for the identification of CA with conventional assessments and investigate their reproducibility and relevance on the assessments. METHODS: Forty patients with biopsy-proven CA were compared with 80 hypertrophied patients matched for mean LV wall thickness. We compared the discriminative abilities of three assessments of RASP to identify CA (visual, quantitative, and semiquantitative). Nine patterns of semiquantitative RASP were investigated; finally, it was defined as "reduction of LS" (≥ -10%) in ≥5 (of 6) basal segments, relative to "preserved LS" (< -15%) in at least one apical segment. RESULTS: The concordance between the two observers for visual RASP was modest (κ = 0.65). On the other hand, the consistency for semiquantitative RASP was perfect (κ = 1.00). The discriminative ability of semiquantitative RASP (area under the curve [AUC]  = 0.74) was significantly better than that of visual RASP (AUC = 0.65) and equivalent to that of binary quantitative RASP. CONCLUSION: Semiquantitative RASP assessment is reproducible and accurately discriminates CA. This simple assessment may help readily refine the risk stratification of patients with diffuse LV hypertrophy.

Intravascular Ultrasound-Derived Virtual Fractional Flow Reserve for the Assessment of Myocardial Ischemia.

BACKGROUND: Fractional flow reserve (FFR) is widely used for the assessment of myocardial ischemia. Intravascular ultrasound (IVUS) is an intracoronary imaging method that provides information about lumen and vessel morphology. Previous studies on the expanded use of IVUS to identify functional ischemia have noted an association between anatomy and physiology, but IVUS-derived minimum lumen area (MLA) has a weak-moderate correlation with myocardial ischemia compared with FFR. We developed a method to calculate FFR using IVUS-derived anatomical information for the assessment of myocardial ischemia. The aims of this study were to investigate the relationship between wire-based FFR and IVUS-derived FFR (IVUS-FFR) and to compare the usefulness of IVUS-FFR and IVUS-derived MLA for functional assessment.Methods and Results:We retrospectively analyzed 50 lesions in 48 patients with coronary stenosis who underwent IVUS and FFR simultaneously. IVUS-FFR was calculated using our original algorithm and fluid dynamics. Mean percent diameter stenosis determined on quantitative coronary angiography and on FFR was 56.4±10.7 and 0.69±0.08, respectively. IVUS-FFR had a stronger linear correlation with FFR (R=0.78, P<0.001; root mean square error, 0.057 FFR units) than with IVUS-derived MLA (R=0.43, P=0.002). CONCLUSIONS: IVUS-FFR may be a more valuable method to identify myocardial ischemia, compared with IVUS-derived MLA.

Incremental value of left atrial active function measured by speckle tracking echocardiography in patients with hypertrophic cardiomyopathy.

PURPOSE: Hypertrophic cardiomyopathy (HCM) impairs left ventricular (LV) diastolic function leading to left atrial (LA) dilatation. Because Doppler echocardiography cannot accurately assess LV diastolic function in hearts with heterogeneous hypertrophy, assessment of LA function might be useful for risk stratification of patients with HCM. This study aimed to elucidate the impact of LA function on outcome in patients with patients. METHODS: Seventy-six patients with HCM who underwent echocardiographic and cardiac magnetic resonance imaging were retrospectively enrolled. Twenty-six control subjects were also included. Using speckle tracking echocardiography, LA function was divided into active and passive strain indices based on the timing of the second positive peak of LA strain rate that occurred during LV systole. RESULTS: Left atrial strain indices of active and passive function were significantly impaired concomitantly with increased LA volume index in HCM patients compared with controls. During follow-up (2.6 ± 1.7 years), 14 patients with HCM developed cardiac events (heart failure hospitalization or atrial fibrillation). The association of LA active strain with cardiac events was independent of and incremental to clinical and echocardiographic parameters (age, gender, E/e', LV global longitudinal strain, and LA volume index) in sequential models. Cardiac events were more frequent in HCM patients with LA active strain <20.3% than with active strain ≥20.3% (P = .01). CONCLUSION: Loss of LA active function was associated with increased cardiac events in patients with HCM.

A Novel Truncating LMNA Mutation in Patients with Cardiac Conduction Disorders and Dilated Cardiomyopathy.

The cardiac phenotype of laminopathies is characterized by cardiac conduction disorders (CCDs) and dilated cardiomyopathy (DCM). Although laminopathies have been considered monogenic, they exhibit a remarkable degree of clinical variability. This case series aimed to detect the causal mutation and to investigate the causes of clinical variability in a Japanese family with inherited CCD and DCM.Of the five family members investigated, four had either CCD/DCM or CCD alone, while one subject had no cardiovascular disease and acted as a normal control. We performed targeted resequencing of 174 inherited cardiovascular disease-associated genes in this family and pathological mutations were confirmed using Sanger sequencing. The degree of clinical severity and variability were also evaluated using long-term medical records. We discovered a novel heterozygous truncating lamin A/C (LMNA) mutation (c.774delG) in all four subjects with CCD. Because this mutation was predicted to cause a frameshift mutation and premature termination (p.Gln258HisfsTer222) in LMNA, we believe that this LMNA mutation was the causal mutation in this family with CCD and laminopathies. In addition, gender-specific intra-familiar clinical variability was observed in this Japanese family where affected males exhibited an earlier onset of CCD and more severe DCM compared to affected females. Using targeted resequencing, we discovered a novel truncating LMNA mutation associated with CCD and DCM in this family characterized by gender differences in clinical severity in LMNA carriers. Our results suggest that in patients with laminopathy, clinical severity may be the result of multiple factors.

Three-dimensional maximum principal strain using cardiac computed tomography for identification of myocardial infarction.

OBJECTIVES: To evaluate the feasibility of three-dimensional (3D) maximum principal strain (MP-strain) derived from cardiac computed tomography (CT) for detecting myocardial infarction (MI). METHODS: Forty-three patients who underwent cardiac CT and magnetic resonance imaging (MRI) were retrospectively selected. Using the voxel tracking of motion coherence algorithm, the peak CT MP-strain was measured using the 16-segment model. With the trans-mural extent of late gadolinium enhancement (LGE) and the distance from MI, all segments were classified into four groups (infarcted, border, adjacent, and remote segments); infarcted and border segments were defined as MI with LGE positive. Diagnostic performance of MP-strain for detecting MI was compared with per cent systolic wall thickening (%SWT) assessed by MRI using receiver-operating characteristic curve analysis at a segment level. RESULTS: Of 672 segments excluding16 segments influenced by artefacts, 193 were diagnosed as MI. Sensitivity and specificity of peak MP-strain to identify MI were 81 % [95 % confidence interval (95 % CI): 74-88 %] and 86 % (81-92 %) compared with %SWT: 76 % (60-95 %) and 68 % (48-84 %), respectively. The area under the curve of peak MP-strain was superior to %SWT [0.90 (0.87-0.93) vs. 0.80 (0.76-0.83), p < 0.05]. CONCLUSIONS: CT MP-strain has a potential to provide incremental value to coronary CT angiography for detecting MI. KEY POINTS: • CT MP-strain allows for three-dimensional assessment of regional cardiac function. • CT-MP strain has high diagnostic accuracy for detecting myocardial infarction. • CT-MP strain may assist in tissue characterisation of myocardium assessed by LGE-MRI. • CT-MP strain provides incremental values to coronary CTA for detecting myocardial infarction.

Pulmonary Hypertension as a Possible Cause of Paradoxical Low-Flow, Low-Gradient Aortic Stenosis.

Paradoxical low-flow, low-gradient aortic stenosis (LFLG AS) is recognized as a subtype of aortic stenosis. A small left ventricular (LV) cavity with marked LV concentric remodeling leads to a reduced stroke volume in this condition. The case is reported of a paradoxical LFLG AS patient who was undergoing treatment for pulmonary hypertension (PH) and interstitial pneumonia associated with scleroderma. Echocardiography demonstrated enlargement of the right ventricle and a diminished LV cavity. Moreover, the aortic valve opening was restricted despite a preserved LV ejection fraction (61%). The patient's aortic valve area (obtained with the continuity equation) was 0.57 cm2 (indexed AVA was 0.39 cm2/m2), and the mean gradient was 16 mmHg. Multi-detector computed tomography findings confirmed that the aortic valve calcification was not severe. The main mechanism responsible for LFLG AS was considered to be a reduced LV cavity secondary to PH, rather than a sclerotic aortic valve. Thus, a decision was taken to treat the patient with additional medical management prior to performing any invasive procedures. It should be borne in mind that PH can lead to paradoxical LFLG AS, and that appropriate treatment should be contemplated depending on the underlying mechanisms. Video 1: Transthoracic echocardiography in the parasternal long-axis view showing right ventricular dilatation and a diminished left ventricular cavity. Video 2: Transthoracic echocardiography in the shortaxis view showing enlargement of the right ventricle and septal flattening due to pulmonary hypertension. Video 3: Transesophageal echocardiography clearly demonstrates an insufficient valve opening.

Clinical Significance of Peripheral Endothelial Function for Left Atrial Blood Stagnation in Nonvalvular Atrial Fibrillation Patients With Low-to-Intermediate Stroke Risk.

BACKGROUND: In patients who have atrial fibrillation (AF) with CHADS2score of 0-1 (categorized as low-to-intermediate risk), there is little information on stratifying the risk of stroke. This study aimed to determine whether impaired endothelial function assessed by reactive hyperemia-peripheral arterial tonometry (RH-PAT) predicted left atrial blood stagnation in these patients. METHODS AND RESULTS: We enrolled 81 consecutive patients with nonvalvular AF. The reactive hyperemia index (RHI) was measured using RH-PAT. Transesophageal echocardiography was performed to determine spontaneous echo contrast (SEC) before direct-current cardioversion or radiofrequency catheter ablation. SEC was found in 49 patients (60%). The RHI was significantly lower in patients with than without SEC. Multivariate analysis demonstrated that RHI was one of the independent determinants of SEC (OR per 0.1, 1.26; 95% CI, 1.11-1.49; P=0.002) in all patients. In addition, RHI was a significant determinant of SEC (AUC, 0.73; 95% CI, 0.63-0.89; P=0.0017) in patients with low-to-intermediate risk. At an RHI cut-off <1.62, the sensitivity and specificity for the identification of patients with SEC were 58% and 89%, respectively. CONCLUSIONS: Impaired endothelial function assessed by RH-PAT might help to predict the presence of SEC in patients with low-to-intermediate risk of stroke. (Circ J 2016; 80: 2117-2123).