Prognostic value of left ventricular dyssynchrony by myocardial perfusion-gated SPECT in patients with normal and abnormal left ventricular functions

Ventricular dyssynchrony late after the Fontan operation is associated with decreased survival

BACKGROUND

Ventricular dyssynchrony and its relationship to clinical outcomes is not well characterized in patients following Fontan palliation.

METHODS

Single-center retrospective analysis of cardiac magnetic resonance (CMR) imaging of patients with a Fontan circulation and an age-matched healthy comparison cohort as controls. Feature tracking was performed on all slices of a ventricular short-axis cine stack. Circumferential and radial strain, strain rate, and displacement were measured; and multiple dyssynchrony metrics were calculated based on timing of these measurements (including standard deviation of time-to-peak, maximum opposing wall delay, and maximum base-to-apex delay). Primary endpoint was a composite measure including time to death, heart transplant or heart transplant listing (D/HTx).

RESULTS

A total of 503 cases (15 y; IQR 10, 21) and 42 controls (16 y; IQR 11, 20) were analyzed. Compared to controls, Fontan patients had increased dyssynchrony metrics, longer QRS duration, larger ventricular volumes, and worse systolic function. Dyssynchrony metrics were higher in patients with right ventricular (RV) or mixed morphology compared to those with LV morphology. At median follow-up of 4.3 years, 11% had D/HTx. Multiple risk factors for D/HTx were identified, including RV morphology, ventricular dilation, dysfunction, QRS prolongation, and dyssynchrony. Ventricular dilation and RV morphology were independently associated with D/HTx.

CONCLUSIONS

Compared to control LVs, single right and mixed morphology ventricles in the Fontan circulation exhibit a higher degree of mechanical dyssynchrony as evaluated by CMR-FT. Dyssynchrony indices correlate with ventricular size and function and are associated with death or need for heart transplantation. These data add to the growing understanding regarding factors that can be used to risk-stratify patients with the Fontan circulation.

Phase analysis for ventricular arrhythmia prediction: A retrospective monocentric cohort study

BACKGROUND

Prediction of ventricular arrhythmias (VA) mostly relies on left ventricular ejection fraction (LVEF), but with limited performance. New echocardiographic parameters such as mechanical dispersion have emerged, but acoustic window sometimes precludes this measurement. Nuclear imaging may be an alternative. We aimed to assess the ability of mechanical dispersion, measured with phase standard deviation (PSD) on radionuclide angiocardiography (RNA), to predict VAs.

METHODS

This retrospective monocentric observational study included all patients who underwent a tomographic RNA from 2015 to 2019. Phase analysis yielded PSD and follow-up was examined to identify VAs, heart transplantation, and death.

RESULTS

The study population consisted of 937 patients, mainly with LVEF ≤ 35% (425, 45%). Most had ischemic (334, 36%) or dilated cardiomyopathies (245, 26%). We identified 86 (9%) VAs. PSD was strongly associated with the occurrence of VA [hazard ratio per 10 ms increase (HR10) 1.12 (1.09-1.16)], heart transplantation [HR10 1.09 (1.06-1.12)], and death [HR10 1.03 (1.00-1.05)]. The association between PSD and VA persisted after adjustment for age, sex, QRS duration, LVEF, global longitudinal strain (GLS), and echocardiography-assessed mechanical dispersion.

CONCLUSION

The occurrence of ventricular arrhythmias was predicted by mechanical dispersion assessed by RNA, even after adjustment for LVEF and GLS.

Improved risk-stratification in heart failure patients with mid-range to severe abnormalities of QRS duration and systolic function using mechanical dyssynchrony assessed by myocardial perfusion-gated SPECT

BACKGROUND

The use of left ventricular mechanical dyssynchrony (LVMD), which has been reported to be responsible for unfavorable outcomes, might improve conventional risk-stratification by clinical indices including QRS duration (QRSd) and systolic dysfunction in patients with heart failure (HF).

METHODS AND RESULTS

Following measurements of 12-lead QRSd and left ventricular ejection fraction (LVEF), three-dimensional (3-D) LVMD was evaluated as a standard deviation (phase SD) of regional mechanical systolic phase angles by gated myocardial perfusion imaging in 829 HF patients. Patients were followed up for a mean period of 37 months with a primary endpoint of lethal cardiac events (CEs). In an overall multivariate Cox proportional hazards model, phase SDs were identified as significant prognostic determinants independently. The patients were divided into 4 groups by combining with the cut-off values of LVEF (35% and 50%) and QRSd (130 ms and 150 ms). The groups with lower LVEF and prolonged QRSd more frequently had CEs than did the other groups. Patient groups with LVEF < 35% and with 35% ≦ LVEF < 50% were differentiated into low-risk and high-risk categories by using an optimal phase SD cut-off value of both QRSd thresholds.

CONCLUSIONS

3-D LVMD can risk-stratify HF patients with mid-range as well as severe abnormalities of QRSd and systolic dysfunction.

Prognostic value of ventricular mechanical dyssynchrony in patients with left ventricular aneurysm: A comparative study of medical and surgical treatment

BACKGROUND

The prognostic value of left ventricular (LV) mechanical dyssynchrony (MD) in patients with LV aneurysm (LVA) is unclear. This study aimed to investigate the long-term prognostic value of LVMD in LVA patients.

METHODS

92 consecutive patients who underwent 99mTc-sestamibi-gated SPECT myocardial perfusion imaging (GSPECT) were retrospectively analyzed and followed-up for a median of 63 months (range, 1-73 months). LV function and histogram bandwidth (BW) were analyzed by QGS software. LVMD was defined by ROC analysis. Cardiac death was defined as the primary endpoint, and the composite of cardiac deaths and severe or acute heart failure (MACE) as the secondary endpoint.

RESULTS

The annual cardiac mortality rate of LVA patients with LVMD and treated by surgical therapy was significantly lower than those treated by medical therapy (2.40% vs. 6.40%, P < .05) but not annual MACE rate (6.61% vs. 10.06%, P > .05). In patients without LVMD, no significant difference in survival and MACE-free survival between medical and surgical treatment. In addition, the occurrence of LVMD is related to the worsen cardiac outcome in terms of MACE and cardiac death, independent of the treatment methods. BW was an independent predictor for MACE (HR 1.010, P < .01) and LVEF (HR .928, P < .05) was an independent predictor for cardiac death in all LVA patients.

CONCLUSIONS

LVA patients with LVMD might be associated with high risk for cardiac death and surgical treatment might improve cardiac survival compared to medical therapy in these patients.

Gated single-photon emission computed tomography myocardial perfusion imaging phase analysis as an imaging biomarker for mortality prediction in heart failure patients undergoing cardiac resynchronization therapy

OBJECTIVE

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure patients. The purpose of this study was to assess the value of gated myocardial perfusion single-photon emission computed tomography (GMPS) phase analysis for predicting survival in heart failure patients undergoing CRT.

METHODS

This retrospective cohort study evaluated heart failure patients who underwent GMPS prior to CRT. Phase histogram bandwidth (PHB) and phase SD (PSD) were calculated using GMPS data. Cox proportional hazards model was used to identify independent predictors of overall survival (OS).

RESULTS

A total of 35 patients (age 65.1 ± 13.3, 27 men and 8 women), who were followed for mean of 4.1 ± 2.9 years, were enrolled in the study. PSD of greater than 45° was found to be an independent predictor of poor OS (hazard ratio = 12.63, P = 0.011) when compared with age (hazard ratio = 1.00, P = 0.922), gender (hazard ratio = 0.31, P = 0.155), NYHA class (hazard ratio = 0.45, P = 0.087), QRS duration greater than 150 ms (hazard ratio = 2.38, P = 0.401), pre-CRT left ventricular ejection fraction (LVEF) (hazard ratio = 0.95, P = 0.175) and etiology of heart failure (hazard ratio = 1.42, P = 0.641). Furthermore, PHB greater than 140° was also found to be an independent predictor of poor OS (hazard ratio = 5.63, P = 0.040) when compared with age, gender, NYHA class, QRS duration greater than 150 ms, pre-CRT LVEF and etiology of heart failure.

CONCLUSIONS

PSD and PHB, measured by GMPS, may serve as biomarkers for the prediction of survival in patients undergoing CRT.

Mechanisms of left ventricular dyssynchrony: A multinational SPECT study of patients with bundle branch block

BACKGROUND

To better understand the mechanisms of left ventricular (LV) mechanical dyssynchrony (LVMD), we explored the relative contributions of QRS duration (QRSd), LV ejection fraction (EF), volumes and scar to LVMD measured by gated single-photon emission tomography in a population of consecutive patients with left bundle branch block (LBBB) and right bundle branch block (RBBB) compared to controls.

METHODS

Myocardial perfusion imaging studies of 275 LBBB and 83 RBBB patients from three centers were analyzed. LVMD was defined as an abnormal phase bandwidth or phase standard deviation. Hospital and gender-specific normal values were obtained from 172 controls.

RESULTS

The prevalence of LVMD was 85 and 40% in LBBB and RBBB, respectively. Ejection fraction, scar severity, and LBBB morphology independently explained 70% of variance seen in PhaseBW. Ejection fraction had the highest area under the curve (AUC 0.918) in the receiver operating characteristics analysis of LVMD with an optimal cut-off of 47% (sensitivity 73% and specificity 98%). Notably, QRSd was not predictive.

CONCLUSION

LV mechanical dysfunction plays a greater role than conduction abnormality in the genesis of LVMD, a finding that is intriguing in the context of contemporary literature which suggests that QRSd is the parameter that is most predictive of CRT response.

The prognostic value of diastolic and systolic mechanical left ventricular dyssynchrony among patients with coronary artery disease and heart failure

BACKGROUND

Prevalence and prognostic value of diastolic and systolic dyssynchrony in patients with coronary artery disease (CAD) + heart failure (HF) or CAD alone are not well understood.

METHODS

We included patients with gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) between 2003 and 2009. Patients had at least one major epicardial obstruction ≥ 50%. We assessed the association between dyssynchrony and outcomes, including all-cause and cardiovascular death.

RESULTS

Of the 1294 patients, HF was present in 25%. Median follow-up was 6.7 years (IQR 4.9-9.3) years with 537 recorded deaths. Patients with CAD + HF had a higher incidence of dyssynchrony than patients with CAD alone (diastolic BW 28.8% for the HF + CAD vs 14.7% for the CAD alone). Patients with CAD + HF had a lower survival than CAD alone at 10 years (33%; 95% CI 27-40 vs 59; 95% CI 55-62, P < 0.0001). With one exception, HF was found to have no statistically significant interaction with dyssynchrony measures in unadjusted and adjusted survival models.

CONCLUSIONS

Patients with CAD + HF have a high prevalence of mechanical dyssynchrony as measured by GSPECT MPI, and a higher mortality than CAD alone. However, clinical outcomes associated with mechanical dyssynchrony did not differ in patients with and without HF.

Synergistic prognostication of left ventricular hypertrophy and three-dimensional mechanical dyssynchrony in heart failure

AIMS

In this study, we investigated the prognostic interplay of left ventricular hypertrophy and mechanical dyssynchrony (LVMD), both of which can be measured three-dimensionally by gated myocardial perfusion imaging (MPI), in patients with chronic systolic heart failure (HF).

METHODS AND RESULTS

In 829 consecutive HF patients with reduced left ventricular ejection fraction less than 50%, LVMD was evaluated as a standard deviation (phase SD) of regional onset of mechanical contraction phase angles. A phase histogram was created by Fourier phase analysis applied to regional time-activity curves obtained by gated MPI. Left ventricular mass index (LVMI) was measured by Corridor 4DM version 6.0. Patients were followed up with a primary endpoint of lethal cardiac events (CE) for a mean interval of 34 months. CE were documented in 223 (27%) of the HF patients. The CE group had a greater phase SD and a greater LVMI than those in the non-CE group. Patients in the CE group had a more advanced age, greater New York Heart Association (NYHA) functional class, left ventricular cavity size, and left atrial diameter or septal E/e' and lower kidney or cardiac function than did patients in the non-CE group. Phase SD > 37 and LVMI > 122.7 g/m2 were identified as optimal cut-off values by receiver operating characteristic analyses for discrimination of the most increased risk HF subgroup from others (P < 0.0001). When classified into four patient subgroups using both cut-off values, HF patients with phase SD > 37 (LVMD) and LVMI > 122.7g/m2 had the highest CE rate among the subgroups (P < 0.0001). Univariate analysis and subsequent multivariate analysis with a Cox proportional hazards model showed that phase SD and LVMI were significant independent predictors of CE with hazard ratios of 1.038 (confidence interval [CI], 1.024-1.051, P < 0.0001) and 1.005 (CI, 1.001-1.008, P = 0.0073), respectively, as well as conventional clinical parameters such as age, NYHA class, estimated glomerular filtration rate (eGFR), and BNP concentration. Patients with increased phase SD and LVMI had incrementally improved prognostic values of clinical parameters including age, NYHA functional class, eGFR, and BNP with increases in the global χ2 value: 5.9 for age; 139.5 for age and NYHA; 157.9 for age, NYHA, and eGFR; 163.9 for age, NYHA, eGFR, and BNP; 183.4 for age, NYHA, eGFR, BNP, and phase SD; and 192.5 for age, NYHA, eGFR, BNP, phase SD, and LVMI.

CONCLUSIONS

Three-dimensionally assessed LVMD has independent prognostic values and can improve the risk stratification of chronic HF patients synergistically in combination with conventional clinical parameters.

Synergistic prognostic implications of left ventricular mechanical dyssynchrony and impaired cardiac sympathetic nerve activity in heart failure patients with reduced left ventricular ejection fraction

Aims

Impairment of cardiac sympathetic innervation is a potent prognostic marker in heart failure, while left ventricular mechanical dyssynchrony (LVMD) has recently been noted as a novel prognosis determinant in heart failure patients with reduced LV ejection fraction (HFrEF). This study was designed to determine the correlation between cardiac sympathetic innervation quantified by metaiodobenzylguanidine (MIBG) activity and LVMD measured by electrocardiogram-gated myocardial perfusion imaging and to evaluate their incremental prognostic values in HFrEF patients.

Methods and results

A total of 570 consecutive HFrEF patients were followed up for 19.6 months with a primary endpoint of lethal cardiac events (CE) such as sudden cardiac death, death due to pump failure and appropriate ICD shock against life-threatening ventricular tachyarrhythmias. Cardiac sympathetic function and innervation were quantified as heart-to-mediastinum ratio (HMR) and washout kinetics of cardiac MIBG activity. LVMD was assessed by a standard deviation (SD) of systolic phase angle in gated myocardial perfusion imaging. Patients with CE (n = 166, 29%) had a significantly lower HMR and a significantly greater phase SD than did non-CE patients: 1.46 ± 0.28 vs. 1.63 ± 0.29, P < 0.0001 and 39.1 ± 11.6 vs. 33.1 ± 10.1, P < 0.0001, respectively. Compared to the single use of optimal cut-offs of late HMR (1.54) and phase SD (38), their combination more precisely discriminated high-risk or low-risk patients from others with log rank values from 7.78 to 65.2 (P = 0.0053 to P ≤ 0.0001). Among significant univariate variables, multivariate Cox proportional hazards model identified NYHA functional class, estimated glomerular filtration rate (eGFR), HMR 1.54 and phase SD 60 as significant determinants of CE with hazard ratios of 3.108 (95% CI, 2.472-3.910; P < 0.0001), 0.988 (95% CI, 0.981-0.996; P = 0.0021), 0.257 (95% CI, 0.128-0.498; P < 0.0001) and 1.019 (95% CI, 1.019-1.037; P = 0.0228), respectively. By combining the four independent determinants, the prognostic powers synergistically (P < 0.0001) increased maximally to 263.8.

Conclusions

Left ventricular mechanical dyssynchrony and impairment of cardiac sympathetic innervation are synergistically related to lethal cardiac events, contributing to better stratification of lethal cardiac event-risks and probably to optimization of therapeutic strategy in patients with HFrEF.

Myocardial stunning-induced left ventricular dyssynchrony on gated single-photon emission computed tomography myocardial perfusion imaging

OBJECTIVES

Myocardial stunning provides additional nonperfusion markers of coronary artery disease (CAD), especially for severe multivessel CAD. The purpose of this study is to assess the influence of myocardial stunning to the changes of left ventricular mechanical dyssynchrony (LVMD) parameters between stress and rest gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

PATIENTS AND METHODS

A total of 113 consecutive patients (88 males and 25 females) who had undergone both stress and rest Tc-sestamibi gated SPECT MPI were retrospectively enrolled. Suspected or known patients with CAD were included if they had exercise stress MPI and moderate to severe myocardial ischemia. Segmental scores were summed for the three main coronary arteries according to standard myocardial perfusion territories, and then regional perfusion, wall motion, and wall thickening scores were measured. Myocardial stunning was defined as both ischemia and wall dysfunction within the same coronary artery territory. Patients were divided into the stunning group (n=58) and nonstunning group (n=55).

RESULTS

There was no significant difference of LVMD parameters between stress and rest in the nonstunning group. In the stunning group, phase SD and phase histogram bandwidth of contraction were significantly larger during stress than during rest (15.05±10.70 vs. 13.23±9.01 and 46.07±34.29 vs. 41.02±32.16, P<0.05). Phase SD and phase histogram bandwidth of relaxation were also significantly larger during stress than during rest (21.21±13.91 vs. 17.46±10.52 and 59.03±37.82 vs. 52.38±36.89, P<0.05).

CONCLUSION

Both systolic and diastolic LVMD parameters deteriorate with myocardial stunning. This kind of change may have incremental values to diagnose CAD.

Mechanical dyssynchrony according to validated cut-off values using gated SPECT myocardial perfusion imaging

BACKGROUND

The aim of this study was to establish different degrees of mechanical dyssynchrony according to validated cut-off (CO) values of myocardial perfusion gated SPECT phase analysis parameters (SD, standard deviation; B, bandwidth; S, skewness; K, kurtosis).

METHODS

Using Emory Cardiac Toolbox™, we prospectively analyzed 408 patients (mean age 64.1 years, 26.7% female), divided into a control group of 150 normal subjects and a validation group of 258 patients (left bundle branch block: 17.8%, right bundle branch block: 8.9%. atrial fibrillation: 16.3%, coronary revascularization: 30%, dilated cardiomyopathy: 7.4%. valvulopathies: 2.7%, ischemic test: 45.3%) with ischemic and non-ischemic cardiac diseases, by means of phase analysis.

RESULTS

Agreement of CO values (SD > 18.4°; B > 51°; S ≤ 3.2; K ≤ 9.3) used to discriminate between normal subjects and patients was strong (c-statistic 0.9; 95% CI 0.98-0.99). Four degrees of dyssynchrony were found according to the number of abnormal phase parameters. All patients with mechanical and electrical criteria for cardiac resynchronization therapy (CCRT) (n: 82) had Grade 2 to 4 (two to four abnormal phase parameters). Agreement of CO values (SD > 40.2°; B > 132°; S ≤ 2.3; K ≤ 4.6) used to discriminate between patients with and without CCRT was strong (c-statistic 0.8; 95% CI 0.79-0.87) but 12% of patients with CCRT did not have any of these abnormal phase parameters.

CONCLUSIONS

The discriminatory capacity of gated SPECT phase analysis parameters between normal subjects and patients, and between patients with and without CCRT, is very good, making it possible to define different degrees of mechanical dyssynchrony.

The prognostic value of mechanical left ventricular dyssynchrony defined by phase analysis from gated single-photon emission computed tomography myocardial perfusion imaging among patients with coronary heart disease

BACKGROUND

The prognostic value of left ventricular dyssynchrony measured by gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) and its relationship to electrical dyssynchrony measured by QRS duration are incompletely understood. The aim of this study was therefore to examine the independent and incremental prognostic value of dyssynchrony in yet the largest group of patients with coronary artery disease (CAD).

METHODS AND RESULTS

Patients presenting for GSPECT- MPI between July 1993 and May 1999 in normal sinus rhythm were identified from the Duke Nuclear Cardiology Databank and the Duke Databank for Cardiovascular Disease (N = 1244). After a median of 4.2 years, 336 deaths occurred. At 8 years, the Kaplan-Meier estimates of the probability of death were 34.0% among patients with a phase bandwidth <100° and 56.8% among those with a bandwidth ≥100°. After adjustment for standard clinical variables, QRS dyssynchrony was independently associated with death (Hazard Ratio (HR), per 10°: 1.092, 95% Confidence Interval (CI) 1.048,1.139, P < .0001). Phase bandwidth was similarly associated with death after clinical adjustment (HR per 10°: 1.056, 95% CI 1.041,1.072, P < .0001). In clinically adjusted models examining QRS duration in addition to phase bandwidth, phase bandwidth had a stronger association with mortality. After accounting for left ventricular ejection fraction (LVEF), neither QRS duration nor phase bandwidth were statistically significant. Among patients with EF >35%, QRS duration and phase bandwidth together provided value above that provided by LVEF alone (P = 0.0181). When examining cardiovascular death, results were consistent with all-cause death.

CONCLUSIONS

Among patients with CAD, mechanical left ventricular dyssynchrony measured by GSPECT MPI has a stronger relationship with outcomes than electrical dyssynchrony measured by QRS duration. After adjustment for baseline characteristics and LVEF, neither mechanical nor electrical dyssynchrony is independently associated with all-cause death or cardiac death. Among patients with EF >35%, mechanical and electrical dyssynchrony together provided prognostic value above that afforded by LVEF.

Yield of left ventricular dyssynchrony by gated SPECT MPI in patients with heart failure prior to implantable cardioverter-defibrillator or cardiac resynchronization therapy with a defibrillator: Characteristics and prediction of cardiac outcome

BACKGROUND

Mechanical left ventricular dyssynchrony (MLVD) might contribute in the therapeutic decision-making in patients with heart failure (HF) prior to cardiac resynchronization therapy (CRT). Our aim was to assess MLVD in patients with HF prior to implantable cardioverter-defibrillator (ICD) compared to patients with CRT-D.

METHODS

In a prospective study, patients with LVEF ≤ 35% who were scheduled for ICD or CRT-D, underwent gated SPECT myocardial perfusion imaging with technetium 99m sestamibi within 3 months prior procedure. MLVD was measured by phase analysis.

RESULTS

The study cohort consisted of 143 patients, 71 with ICD and 72 with CRT-D. Age 68.3 ± 11 and LVEF 24 ± 6%. Phase standard deviation (SD) was 62.5 ± 18 and 59.7 ± 20 (P = NS), respectively. During follow-up of 23.7 ± 12.1 months, there were 10 vs 14 cardiac death in ICD and CRT-D, respectively (P = NS), hospitalization for HF, in 34 vs 53 (P < .001). In multivariate analysis, Phase SD was the independent predictor for cardiac death [HR 2.66 (95% CI 1.046-6.768), P = .04]. Kaplan-Meier curves of phase SD of 60° significantly identified ICD patients with and without cardiac deaths and hospitalization for HF exacerbation.

CONCLUSIONS

MLVD by phase SD can identify patients with cardiac events and predict cardiac death in patients treated with ICD.

Prevalence and predictors of left intraventricular dyssynchrony determined by phase analysis in patients undergoing gatedSPECT myocardial perfusion imaging

Left ventricular dyssynchrony (LVD) is an independent predictor of adverse cardiovascular events, death, and progression to heart failure. Myocardial perfusion imaging (MPI) with ECG-gated single-photon emission computed tomography (SPECT) can be used to diagnose LVD rapidly and automatically using phase analysis (PA). The objective of this study was to evaluate the prevalence and predictors of LVD in patients undergoing MPI. Clinical, electrocardiographic, and scintigraphic data from 1000 patients who underwent MPI with ECG-gated SPECT over a period of 1 year were analyzed retrospectively. TheEmoryCardiac Toolboxsoftware was used for PA, and LVD was diagnosed based on the following criteria: standard deviation of LV phase distribution ≥43° and/or phase histogram ≥140° in the resting and/or stress phase of the examination. Several variables were evaluated using univariate and multivariate analyses. The prevalence of LVD in the study population was 6.5 %, and the average age was 63.6 ± 12 years. The variables significantly associated with LVD were male gender, obesity, hypertension, diabetes, dyslipidemia, coronary artery disease (CAD), QRS interval ≥120 ms, LV dysfunction, and myocardial perfusion defects (especially fixed defects) on MPI. Although the PA parameters were greater at rest, both phases could be used for diagnosis. Multivariate analysis revealed that the variables significantly associated with LVD were male sex, obesity, history of CAD, and QRS interval ≥120 ms. The overall prevalence of LVD was 6.5 % in patients undergoing MPI in this study, and it reached 42 % in the presence of certain risk factors.

Radionuclide Assessment of Left Ventricular Dyssynchrony

Phase analysis of gated myocardial perfusion single-photon emission computed tomography is a widely available and reproducible measure of left ventricular (LV) dyssynchrony, which also provides comprehensive assessment of LV function, global and regional scar burden, and patterns of LV mechanical activation. Preliminary studies indicate potential use in predicting cardiac resynchronization therapy response and elucidation of mechanisms. Because advances in technology may expand capabilities for precise LV lead placement in the future, identification of specific patterns of dyssynchrony may have a critical role in guiding cardiac resynchronization therapy.

Review of cardiovascular imaging in The Journal of Nuclear Cardiology in 2014: Part 2 of 2: Myocardial perfusion imaging

In this new feature of The Journal of Nuclear Cardiology we will summarize key articles that were published in the Journal in the previous year. In the first article of this 2-part series we concentrated on publications dealing with cardiac positron emission tomography, computed tomography, and neuronal imaging. This review will focus on myocardial perfusion imaging summarizing advances in the field including in diagnosis, prognosis, appropriateness, and safety of testing.

Update on cardiac imaging techniques 2014

In this article, we review the contributions of the most important imaging techniques used in cardiology, reported in 2014. Echocardiography remains the cornerstone for diagnosing and monitoring valvular heart disease, and there has been a continuing effort to improve quantification of this condition and obtain prognostic parameters for follow-up. The study of regional myocardial function is anchored in the diagnosis of subclinical ventricular dysfunction, and 3-dimensional transesophageal echocardiography has become the perfect ally in interventional procedures for structural heart disease. Cardiac magnetic resonance imaging and cardiac computed tomography are the focus of most publications on cardiac imaging in ischemic heart disease, reflecting their consolidated use in clinical practice. Nuclear medicine excels in the study of myocardial viability after interventional treatment of acute coronary syndromes and its performance is validated in the diagnosis of ischemic heart disease.