The reliability and utility of on-site CT-derived fractional flow reserve (FFR) based on fluid structure interactions: comparison with FFRCT based on computational fluid dynamics, invasive FFR, and resting full-cycle ratio.

Fractional flow reserve (FFR) derived off-site by coronary computed tomography angiography (CCTA) (FFRCT) is obtained by applying the principles of computational fluid dynamics. This study aimed to validate the overall reliability of on-site CCTA-derived FFR based on fluid structure interactions (CT-FFR) and assess its clinical utility compared with FFRCT, invasive FFR, and resting full-cycle ratio (RFR). We calculated the CT-FFR for 924 coronary vessels in 308 patients who underwent CCTA for clinically suspected coronary artery disease. Of these patients, 35 patients with at least one obstructive stenosis (> 50%) detected on CCTA underwent both CT-FFR and FFRCT for further investigation. Furthermore, 24 and 20 patients underwent invasive FFR and RFR in addition to CT-FFR, respectively. The inter-observer correlation (r) of CT-FFR was 0.93 (95% confidence interval [CI] 0.85-0.97, P < 0.0001) with a mean absolute difference of - 0.0042 (limits of agreement - 0.073, 0.064); 97.3% of coronary arteries without obstructive lesions on CCTA had negative results for ischemia on CT-FFR (> 0.80). The correlation coefficient between CT-FFR and FFRCT for 105 coronary vessels was 0.87 (95% CI 0.82-0.91, P < 0.0001) with a mean absolute difference of - 0.012 (limits of agreement - 0.12, 0.10). CT-FFR correlated well with both invasive FFR (r = 0.66, 95% CI 0.36-0.84, P = 0.0003) and RFR (r = 0.78, 95% CI 0.51-0.91, P < 0.0001). These data suggest that CT-FFR can potentially substitute for FFRCT and correlates closely with invasive FFR and RFR with high reproducibility. Our findings should be proven by further clinical investigation in a larger cohort.

Left-atrial volume reduction reflects improvement of cardiac sympathetic nervous function in patients with severe aortic stenosis after transcatheter aortic valve replacement.

Trans-catheter aortic valve replacement (TAVR) is an excellent alternative intervention for surgical aortic valve replacement. Cardiac sympathetic nervous (CSN) function and left atrial (LA) volume are both important prognostic factors in patients with aortic stenosis (AS) after TAVR. The relationship between the two clinical factors is unknown, however. This retrospective observational study aimed to assess the correlation between CSN function and LA volume in 48 symptomatic patients with severe AS (median age: 85 years, IQR 82-88 years; 81% female) before and after TAVR. CSN function was assessed by performing 123I-metaiodobenzylguanidine (MIBG) scintigraphy before and 6 months after TAVR, and the delayed heart-to-mediastinum ratio (dHMR) and washout rate (WR) were calculated. We also performed transthoracic echocardiography near the same time. TAVR improved the dHMR, WR, and LA volume index (LAVI) (dHMR: median 2.89 [IQR 2.62-3.23] vs. 2.98 [2.49-3.25], p = 0.0182; WR: 28% [24-38] vs. 23% [16-32], p < 0.0001; LAVI: 47.7 mL/m2 [37.8-56.3] vs. 41.2 mL/m2 [33.7-56.1], p = 0.0024). In multiple linear regression analysis, the percentage change in LAVI from baseline to post-TAVR (∆LAVI%) was an independent predictor of change in dHMR from baseline to post-TAVR (ß = - 0.35, p = 0.0110). In conclusion, LA volume reduction reflected CSN functional improvement after TAVR. In patients with TAVR, ∆LAVI% might be a valuable parameter for evaluating CSN functional recovery.

P-Wave Terminal Force V1 Is Associated with Left Ventricular Diastolic Function in Patients with No Significant Perfusion Abnormality.

P-wave terminal force in lead V1 (PTFV1) is a marker of increased left atrial (LA) overload. Whether PTFV1 is associated with left ventricular (LV) diastolic function remains undetermined. We tested the hypothesis that PTFV1 is associated with LV diastolic parameters derived from gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with no significant perfusion abnormalities.The study population included 158 patients with preserved ejection fraction and no significant perfusion abnormalities. The amplitude and duration of the P-wave negative phase in lead V1 were measured using an electrocardiogram, and PTFV1 was calculated. The peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters using gated SPECT.PTFV1 showed a weak correlation with the LA volume index (r = 0.31; P < 0.001). Significant associations were observed between PTFV1 and PFR (r = -0.27; P < 0.001) and 1/3 MFR (r = -0.26; P = 0.001). A multivariate linear regression analysis showed that age (ß = -0.26; P < 0.001), LV end-diastolic volume index (ß = -0.27; P = 0.001), and PTFV1 (ß = -0.15; P = 0.036) were significant factors associated with PFR. Moreover, male gender (ß = -0.16; P = 0.041), LV mass index (ß = -0.17; P = 0.046), and PTFV1 (ß = -0.17; P = 0.022) were significant factors associated with the 1/3 MFR.PTFV1 is associated with LV diastolic function, as derived from gated SPECT in patients with no significant perfusion abnormalities.

Factors Influencing Cardiac Sympathetic Nervous Function in Patients With Severe Aortic Stenosis: Assessment by 123I-Metaiodobenzylguanidine Myocardial Scintigraphy.

BACKGROUND: Numerous studies have shown that 123I-metaiodobenzylguanidine (MIBG) scintigraphy, an index of cardiac sympathetic nervous (CSN) activity, is useful for predicting prognosis in patients with heart failure. However, the factors influencing the CSN activity of patients with severe aortic stenosis (AS) remain unclear. METHODS: We enrolled 91 patients with severe AS who underwent 123I-MIBG scintigraphy, coronary computed tomography (CCT), and transthoracic echocardiography. When CCT angiography (CCTA) showed an obstructive epicardial artery, invasive coronary angiography was performed within 1 week of CCTA. RESULTS: There were 21 male and 70 female patients with a mean age of 84±5 years. Eighty-five (85) patients (93%) had hypertension and 13 patients (14%) had diabetes. Two (2) patients (2%) had previous myocardial infarction and eight (9%) had a previous coronary intervention. All patients had severe AS: aortic valve area was 0.63±0.18 cm2 and the mean pressure gradient was 56±19 mmHg. Regarding 123I-MIBG parameters, early heart-to-mediastinum (H/M) ratio was 3.1±0.5, delayed H/M ratio was 2.8±0.6, and the washout rate (WR) was 35%±13%. Multivariable linear regression analysis showed that coronary artery disease (ß=-0.30, p=0.002) was an independent predictor of delayed H/M ratio, and that aortic valve area (ß=-0.20, p=0.048) was an independent predictor of WR. CONCLUSIONS: Our findings suggest that coronary artery disease is an independent predictor of delayed H/M ratio, and aortic valve area is an independent predictor of WR in patients with severe AS.

Impact of Percutaneous Edge-to-Edge Repair in Patients With Atrial Functional Mitral Regurgitation.

BACKGROUND: The aim of this study was to clarify the clinical outcomes of patients with atrial functional mitral regurgitation (FMR) who underwent the MitraClip procedure compared with those with conventional FMR and sinus rhythm (SR).Methods and Results:Of 303 patients with FMR who underwent the MitraClip procedure, 40 with "atrial-FMR" defined as FMR with permanent atrial fibrillation and normal left ventricular (LV) function/size and 115 with "sinus-FMR" defined as FMR with SR and LV dysfunction were reviewed. Transthoracic and 3D transesophageal echocardiography, and the cardiac complication rate (composite of all-cause death, heart failure admission, mitral valve (MV) surgery, and redo MitraClip procedure) during the 12-month follow-up were compared between the groups. After the MitraClip procedure, reductions in the mitral annular area and its anteroposterior dimension and in the leaflet closure area were observed in both groups. MV orifice area was smaller with greater transmitral pressure gradient (P<0.05) after the procedure in atrial-FMR patients than in those with sinus-FMR. The prevalence of residual MR was similar, but significant tricuspid regurgitation (TR) was more prevalent in the atrial-FMR group at follow-up. Cardiac complication rate was comparable between groups (20% vs. 25%, P=0.63). CONCLUSIONS: Reduction of MR occurred in atrial-FMR probably because of the increase in leaflet coaptation area. Significant TR was more common after the MitraClip procedure in patients with atrial-FMR than with sinus-FMR. However, mid-term outcomes were comparable between patients with atrial-FMR and sinus-FMR.

Left ventricular outflow tract area after percutaneous transseptal transcatheter mitral valve implantation: A three-dimensional transesophageal echocardiography study.

BACKGROUND: Left ventricular (LV) outflow tract (LVOT) obstruction increases mortality in patients undergoing transcatheter mitral valve implantation (TMVI) in degenerated bioprostheses, annuloplasty rings, and native mitral valves. We aimed to evaluate the LVOT area after TMVI using 3-dimensional (3D) transesophageal echocardiography (TEE) and to investigate the preprocedural cardiac geometry that affects the LVOT area after TMVI. METHODS: We retrospectively reviewed echocardiography data in 43 patients who had TMVI. A change in pressure gradient across LVOT from before to after TMVI (∆PG) and postprocedure 3D LVOT cross-sectional area at the level of the most distal portion of the mitral valve stent that was closest to the LV apex were assessed as evidence of LVOT narrowing. RESULTS: Transcatheter mitral valve implantation with the use of balloon-expandable valve system was performed for 24 bioprostheses, 7 annuloplasty rings, and 12 native valves. Compared to patients without increase in LVOT gradient (∆PG <10 mm Hg; n = 33), patients with increase in LVOT gradient (∆PG ≥10 mm Hg; n = 10) had smaller LV end-systolic volume (LVESV), greater LV ejection fraction (LVEF), and smaller aorto-mitral (AM) angle. The LVOT area at the valve stent distal edge showed strong association with ∆PG (r = -.68, P < .0001). Only a small AM angle was associated with a small LVOT area at the valve stent distal edge on multivariable analysis, independent of LVESV and LVEF. CONCLUSION: Small LV size, preserved LVEF, and small AM angle were associated with LVOT narrowing. 3D-derived AM angle might be independently associated with LVOT narrowing in patients undergoing transcatheter mitral valve-in-valve, valve-in-ring, and valve-in-native valve implantation, independent of LVESV and LVEF.

The Monocyte to High-Density Lipoprotein Cholesterol Ratio Is Associated with Left Ventricular Diastolic Function in Patients with No Significant Perfusion Abnormality.

The monocyte to high-density lipoprotein cholesterol (HDL-C) ratio has been considered to be a prognostic marker. Whether this ratio is associated with left ventricular (LV) diastolic function remains undetermined. We tested the hypothesis that the monocyte to HDL-C ratio is associated with LV diastolic parameters derived from gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with no significant perfusion abnormality.The study population included 196 patients with no significant perfusion abnormalities and preserved ejection fraction. The peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters using gated SPECT. Monocyte counts and plasma HDL-C levels were also examined.Significant associations were observed between the monocyte to HDL-C ratio and PFR (r = -0.20; P = 0.005) and 1/3 MFR (r = -0.19; P = 0.009). Multivariate linear regression analysis was performed to determine factors associated with LV diastolic parameters. Age (ß = -0.27; P < 0.001), LV end-diastolic volume (ß = -0.19; P = 0.034), and monocyte to HDL-C ratio (ß = -0.15; P = 0.027) were determined to be significantly associated with PFR. Moreover, age (ß = -0.13; P = 0.007), LV mass index (ß = -0.18; P = 0.037), and the monocyte to HDL-C ratio (ß = -0.13; P = 0.045) were significantly associated with 1/3 MFR.These results demonstrated that the monocyte to HDL-C ratio is associated with LV diastolic function, as derived from gated SPECT in patients with no significant perfusion abnormality.

Frontal QRS-T angle and left ventricular diastolic function assessed by ECG-gated SPECT in the absence of significant perfusion abnormality.

The frontal QRS-T angle, defined as the angle between QRS and T-wave axes, has recently become an area of research interest. We tested the hypothesis that the frontal QRS-T angle is associated with left ventricular (LV) diastolic function in the absence of significant perfusion abnormality using ECG-gated SPECT. One hundred twenty eight patients with no significant perfusion abnormality and preserved LV ejection fraction were enrolled. The peak filling rate (PFR) and the one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters on ECG-gated SPECT. There were 115 male and 13 female patients with a mean age of 70 ± 9 years. The PFR and 1/3 MFR were 2.1 ± 0.4/s and 1.2 ± 0.3/s, respectively. The frontal QRS-T angle was 33° ± 31°, ranging from 0° to 151°. There were significant associations of frontal QRS-T angle with PFR (r = - 0.29, p = 0.001) and 1/3 MFR (r = - 0.30, p < 0.001). Multivariate linear regression analysis showed that age (ß = - 0.25, p = 0.003), heart rate (ß = 0.26, p = 0.002), LV ejection fraction (ß = 0.43, p < 0.001) and frontal QRS-T angle (ß = - 0.16, p = 0.03) were significant factors associated with PFR. Also, heart rate (ß = - 0.32, p < 0.001), LV mass index (ß = - 0.19, p = 0.03), LV ejection fraction (ß = 0.30, p < 0.001) and frontal QRS-T angle (ß = - 0.26, p = 0.002) were significant factors associated with 1/3 MFR. Our data suggested that the frontal QRS-T angle was associated with LV diastolic function in the absence of significant perfusion abnormality.

Associations of left ventricular shape with left ventricular volumes and functions assessed by ECG-gated SPECT in patients without significant perfusion abnormality.

Left ventricular (LV) remodeling often results from conditions with an elevated LV hemodynamic load or after myocardial infarction. The present study was undertaken to investigate the associations of LV shape with LV volumes and functions in patients without significant perfusion abnormality. One hundred and sixty-seven patients without significant perfusion abnormality on ECG-gated SPECT were enrolled. LV ejection fraction (LVEF) was obtained for assessing LV systolic function. Peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained for assessing LV diastolic function. LV shape index (LVSI) was defined as the ratio of the maximum three-dimensional short- and long-axis LV dimension, and varies from 0 (line) to 1 (sphere). There were 125 male and 42 female patients with a mean age of 70 ± 8 years. End-systolic LVSI was 0.49 ± 0.07 (0.34-0.65). End-systolic LVSI was associated with LV end-diastolic volume (r = 0.51, p < 0.001) and LV end-systolic volume (LVESV) (r = 0.64, p < 0.001), and was inversely associated with LVEF (r = - 0.69, p < 0.001), PFR (r = - 0.45, p < 0.001) and 1/3 MFR (r = - 0.26, p = 0.008). End-systolic LVSI was increased with increased LVESV, and was not any more with LVESV of > 40 ml. Multivariate liner regression analysis showed that age (ß = 0.16, p = 0.01), LVESV (ß = 0.20, p = 0.03) and LVEF (ß = - 0.53, p < 0.001) were significantly associated with end-systolic LVSI. Our data suggest that end-systolic LVSI, a measurement of LV shape, has close correlations with LV volumes and functions in patients without significant perfusion abnormality.

Effects of aging on coronary flow reserve in patients with no evidence of myocardial perfusion abnormality.

Coronary flow reserve (CFR) reflects the functional capacity of microcirculation to adapt to blood demand during increased cardiac work. We tested the hypothesis that aging had impacts on coronary flow velocities and CFR in patients with no evidence of myocardial perfusion abnormality on single photon emission computed tomography (SPECT). Seventy-six patients undergoing transthoracic Doppler echocardiography with no evidence of myocardial perfusion abnormality on SPECT were enrolled in this study. CFR was defined as the ratio of hyperemic to resting peak diastolic coronary flow velocity. Patients were divided into the three groups based on age: 17 patients aged less than 70 years (Group I), 38 patients aged 70-79 years (Group II), and 21 patients aged 80 years or more (Group III). Compared with Group I, CFR was significantly lower in Group II (p < 0.01) and Group III (p < 0.01). Multivariate linear regression analysis showed that female (ß = - 0.26, p = 0.03), cigarette smoking (ß = - 0.32, p = 0.004), hemoglobin level (ß = - 0.40, p = 0.001) and LV mass index (ß = 0.24, p = 0.03) were determinants for resting coronary flow velocity. On the other hand, age (ß = -0.30, p = 0.008), hemoglobin level (ß = -0.47, p < 0.001) and LV mass index (ß = 0.24, p = 0.04) were determinants for hyperemic coronary flow velocity. Age was only determinant for CFR (ß = -0.48, p < 0.001). Our data suggested that that aging had a decreased effect on hyperemic coronary flow velocity rather than resting coronary flow velocity, and was further associated with impaired CFR in patients with no evidence of myocardial perfusion abnormality.

Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement on Changes in Cardiac Sympathetic Nervous Function.

The impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) on changes in cardiac sympathetic nervous (CSN) function remains unclear. Using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, we investigated the impact of PPM after TAVR on CSN activity.We enrolled 44 of 117 patients with severe aortic stenosis who underwent TAVR for analysis in the present study. We conducted 123I-MIBG scintigraphy at baseline and at about 9 months after TAVR. Differences between baseline and post-TAVR 123I-MIBG parameters were compared between cases with and without PPM.There were 17 and 27 patients with and without PPM, respectively. Those without PPM exhibited significantly decreased left ventricular mass index (122 ± 36 g/m2 versus 108 ± 30 g/m2, P < 0.001) following TAVR, whereas those with PPM did not (117 ± 21 g/m2 versus 110 ± 17 g/m2, P = 0.09). Significant improvements in delayed heart-to-mediastinum (H/M) ratio (2.8 ± 0.4 versus 3.0 ± 0.4, P = 0.004) and washout rate (WR) (33% ± 10% versus 24% ± 12%, P < 0.001) were observed after TAVR in patients without PPM but not in those with PPM. Multivariable linear regression analysis revealed PPM to be a negative predictor of improvements in delayed H/M ratio and WR.Delayed H/M ratio and WR improve significantly after TAVR in the absence of PPM, whereas these improvements are not observed in patients with PPM. Hence, the presence of PPM is a negative predictor of improvements in delayed H/M ratio and WR in patients undergoing TAVR.

Effects of deep inspiration on QRS axis, T-wave axis and frontal QRS-T angle in the routine electrocardiogram.

The frontal QRS-T angle on the electrocardiogram has been described as a variable of ventricular repolarization. We evaluated how deep inspiration affected QRS axis, T-wave axis and frontal QRS-T angle. We also assessed the effects on left ventricular volume on the association using myocardial perfusion SPECT. Fifty patients undergoing ECGs both in resting state and in deep inspiration and subsequent SPECT were enrolled. Frontal QRS-T angle was defined as the absolute value of the difference between the frontal QRS axis and T-wave axis. Change in frontal QRS-T angle was calculated using (QRS-T angle in deep inspiration-QRS-T angle in resting state). In resting state, QRS axis and T-wave axis were 20.9° ± 30.0° and 40.9° ± 36.1°, respectively. Frontal QRS-T angle was 35.9° ± 36.1°. Deep inspiration caused rightward shifts of QRS axis (42.3° ± 29.5°, p < 0.001) and T-wave axis (49.5° ± 39.7°, p < 0.001). However, deep inspiration did not affect frontal QRS-T angle (33.9° ± 35.8°, p = 0.44). Frontal QRS-T angle in deep inspiration had good correlation (r = 0.87, p < 0.001) and agreement with that in resting state. Left ventricular (LV) end-diastolic volume had a significant association with change in frontal QRS-T angle (r = 0.29, p = 0.04). Our data suggest that frontal QRS-T angle in deep inspiration has a good correlation with that in resting state, and the agreement is acceptable. In patients with dilated LV, QRS-T angle in deep inspiration may be susceptible to the overestimation.

Myocardial perfusion defect assessed by single-photon emission computed tomography and frontal QRS-T angle in patients with prior anterior myocardial infarction.

The frontal QRS-T angle is one of the markers of ventricular repolarization. We sought to assess the effects of myocardial perfusion defect on QRS-T angle in patients with prior anterior myocardial infarction (MI). Seventy-one patients with prior anterior MI and 71 age- and sex-matched control subjects having no myocardial perfusion defect were selected. Frontal QRS-T angle was defined as the absolute value of the difference between the frontal plane QRS axis and T-wave axis. The extent of myocardial perfusion defect was determined using myocardial perfusion single-photon emission computed tomography (SPECT). The extent of myocardial perfusion defect of patients with prior anterior MI was 21.8 ± 13.7%. Frontal QRS-T angle was significantly larger in patients with prior anterior MI than control subjects (82° ± 49° vs 30° ± 26°, p < 0.001). Prevalence of abnormal frontal QRS-T angle defined as more than 90° was significantly higher in patients with prior anterior MI than control subjects (42% vs 4%, p < 0.001). Multivariate linear regression analysis showed that age (ß=0.18, p = 0.02) and myocardial perfusion defect (ß = 0.46, p = 0.02) were independent determinants of frontal QRS-T angle. Our results suggest that the extent of myocardial perfusion defect is an independent determinant of frontal QRS-T angle in patients with prior anterior MI.

Coronary Artery Calcium Is Associated with Left Ventricular Diastolic Function Independent of Myocardial Ischemia.

It has been shown in several studies that coronary artery calcium (CAC) burden or CAC progression is associated with heart failure. We tested the hypothesis that the extent of CAC is associated with left ventricular (LV) diastolic parameters derived from gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with no evidence of myocardial ischemia.157 patients undergoing coronary computed tomography (CT), gated SPECT, and transthoracic echocardiography (TTE) were enrolled in this study. The CAC score was calculated according to the Agatston method. The peak filling rate (PFR) and the one-third mean filling rate (1/3MFR) were obtained as LV diastolic parameters.There were 139 patients with CAC and 18 patients without. The CAC score ranged from 0 to 4,976. There were no significant differences in the LV end-diastolic volume (LVEDV) (61 ± 21 mL versus 62 ± 22 mL, P = 0.79) and LV ejection fraction (LVEF) (66 ± 9% versus 68 ± 9%, P = 0.43). Patients with CAC had lower PFR than those without (2.2 ± 0.5 EDV/s versus 2.6 ± 0.7 EDV/s, P = 0.03). Multivariate linear regression analysis showed that ln (CAC score + 1) was significantly associated with PFR (ß = -0.20, P = 0.01) and 1/3MFR (ß = -0.18, P = 0.049).Our data suggest that the extent of CAC is inversely associated with LV diastolic parameters derived from gated SPECT independent of myocardial ischemia.

Effects of aortic tortuosity on left ventricular diastolic parameters derived from gated myocardial perfusion single photon emission computed tomography in patients with normal myocardial perfusion.

Aortic tortuosity is often found on chest radiograph, especially in aged patients. We tested the hypothesis that aortic tortuosity was associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion. One-hundred and twenty-two patients with preserved LV ejection fraction and normal myocardial perfusion were enrolled. Descending aortic deviation was defined as the horizontal distance from the left line of the aortic knob to the most prominent left line of the descending aorta. This parameter was measured for the quantitative assessment of aortic tortuosity. Peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained from redistribution images as LV diastolic parameters. Descending aortic deviation ranged from 0 to 22 mm with a mean distance of 4.5 ± 6.3 mm. Descending aortic deviation was significantly correlated with age (r = 0.38, p < 0.001) and estimated glomerular filtration rate (eGFR) (r = - 0.21, p = 0.02). Multivariate linear regression analysis revealed that eGFR (ß = 0.23, p = 0.02) and descending aortic deviation (ß = - 0.23, p = 0.01) were significantly associated with PFR, and that only descending aortic deviation (ß = - 0.21, p = 0.03) was significantly associated with 1/3 MFR. Our data suggest that aortic tortuosity is associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion.

Effect of fibrillatory wave amplitude on coronary blood flow as assessed by thrombolysis in myocardial infarction frame count in patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia, characterized by a lack of atrial contraction and an irregular ventricular rhythm. We assessed the effect of fibrillatory wave amplitude on coronary blood flow in patients with AF using the thrombolysis in myocardial infarction (TIMI) frame count. Sixty-one patients with AF persisting for longer than 30 days were included. For controls, 61 age- and sex-matched patients with sinus rhythm were selected. Coarse AF was defined as any fibrillatory wave ≥ 1 mm and fine AF as any fibrillatory wave < 1 mm. Mean TIMI frame count was significantly higher in patients with AF than in those with sinus rhythm (18 ± 4 vs 30 ± 11, p < 0.001). Multivariate analysis showed that AF was the only determinant of mean TIMI frame count (ß = 0.48, p < 0.001). Among patients with AF, 32 had coarse AF and 29 had fine AF. Left atrial volume index (54 ± 14 vs 64 ± 21 ml/m2, p = 0.03) was significantly larger, and mean TIMI frame count (26 ± 7 vs 35 ± 12, p < 0.001) was significantly higher in patients with fine AF than in those with coarse AF. Multivariate analysis showed that hypertension (ß = - 0.29, p = 0.01) and a fine fibrillatory wave (ß = 0.33, p = 0.007) were determinants of mean TIMI frame count. Our data suggest that coronary blood flow is reduced in patients with AF compared with those with sinus rhythm, and that a fine fibrillatory wave is a major determinant of reduced coronary blood flow in patients with AF.

Association of QRS duration with left ventricular volume and ejection fraction after anterior myocardial infarction assessed by gated single photon emission computed tomography.

BACKGROUND: Even intermediate QRS prolongation without bundle branch block is associated with worse clinical outcome after myocardial infarction (MI). We assessed the association of QRS duration with left ventricular (LV) volume and ejection fraction after anterior MI by using quantitative gated single photon emission computed tomography (SPECT). METHODS: Eighty-two patients with prior anterior MI were enrolled. Intermediate QRS prolongation was defined as QRS duration ≥100 ms without bundle branch block. Quantitative analysis of thallium SPECT was performed on the redistribution image. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF) were obtained. RESULTS: There were 25 patients with intermediate QRS prolongation and 57 patients with normal QRS duation. Compared to patients with normal QRS duration, patients with intermediate QRS prolongation had larger LVEDV (137.4 ± 75.1 ml vs 87.9 ± 43.6 ml, p = .004), larger LVESV (89.9 ± 69.6 ml vs 49.2 ± 35.5 ml, p = .009) and lower LVEF (39.3 ± 14.6% vs 47.6 ± 12.0%, p = .02). QRS duration was positively associated with LVEDV (r = 0.49, p < .001) and LVESV (r = 0.47, p < .001), and was inversely associated with LVEF (r= -0.32, p < .001). Multivariate analysis showed that male sex (ß = 0.22, p = .04), QRS duration (ß = 0.34, p = .002) and number of abnormal Q waves (ß = 0.37, p < .001) were associated with LVEDV. QRS duration (ß= -0.32, p = .003) and number of abnormal Q waves (ß = -0.40, p < .001) were associated with LVEF. CONCLUSIONS: Our results suggest that QRS duration as well as number of abnormal Q waves is independently associated with LV volume and ejection fraction after anterior MI.