Does targeted positioning of the left ventricular pacing lead towards the latest local electrical activation in cardiac resynchronization therapy reduce the incidence of death or hospitalization for heart failure?

BACKGROUND: Cardiac resynchronization therapy (CRT) improves symptoms, health-related quality of life and long-term survival in patients with systolic heart failure (HF) and shortens QRS duration. However, up to one third of patients attain no measurable clinical benefit from CRT. An important determinant of clinical response is optimal choice in left ventricular (LV) pacing site. Observational data have shown that achieving an LV lead position at a site of late electrical activation is associated with better clinical and echocardiographic outcomes compared to standard placement, but mapping-guided LV lead placement towards the site of latest electrical activation has never been investigated in a randomized controlled trial (RCT). The purpose of this study was to evaluate the effect of targeted positioning of the LV lead towards the latest electrically activated area. We hypothesize that this strategy is superior to standard LV lead placement. METHODS: The DANISH-CRT trial is a national, double-blinded RCT (ClinicalTrials.gov NCT03280862). A total of 1,000 patients referred for a de novo CRT implantation or an upgrade to CRT from right ventricular pacing will be randomized 1:1 to receive conventional LV lead positioning preferably in a nonapical posterolateral branch of the coronary sinus (CS) (control group) or targeted positioning of the LV lead to the CS branch with the latest local electrical LV activation (intervention group). In the intervention group, late activation will be determined using electrical mapping of the CS. The primary endpoint is a composite of death and nonplanned HF hospitalization. Patients are followed for a minimum of 2 years and until 264 primary endpoints occurred. Analyses will be conducted according to the intention-to-treat principle. Enrollment for this trial began in March 2018, and per April 2023, a total of 823 patients have been included. Enrollment is expected to be complete by mid-2024. CONCLUSIONS: The DANISH-CRT trial will clarify whether mapping-guided positioning of the LV lead according to the latest local electrical activation in the CS is beneficial for patients in terms of reducing the composite endpoint of death or nonplanned hospitalization for heart failure. Results from this trial are expected to impact future guidelines on CRT. GOV IDENTIFIER: NCT03280862.

Left axis deviation in patients with left bundle branch block is a marker of myocardial disease associated with poor response to cardiac resynchronization therapy.

AIMS: Patients with left axis deviation (LAD) and left bundle branch block (LBBB) show less benefit from cardiac resynchronization therapy (CRT) compared to other LBBB-patients. This study investigates the reasons for this. METHODS: Sixty-eight patients eligible for CRT were included. Patients were divided into groups according to QRS-axis; normal axis (NA), left axis deviation (LAD) and right axis deviation (RAD). Before CRT implantation CMR imaging was performed to evaluate scar tissue. Echocardiography was performed before and after implantation. The electrical substrate was assessed by measuring interlead electrical delays. Response was evaluated after 8 months by left ventricular (LV) remodelling and clinical response. RESULTS: Forty-four (65%) patients were responders in terms of LV remodelling. The presence of LAD was found to be independently associated with a poor LV remodelling non-response OR 0.21 [95% CI 0.06-0.77] (p = 0.02). Patients with axis deviation had more myocardial scar tissue (1.3 ±â€¯0.6 vs. 0.9 ±â€¯0.6, P = 0.04), more severe LV hypertrophy (14 (64%) and 6 (60%) vs. 7 (29%), P = 0.05) and tended to have a shorter interlead electrical delay than patients with NA (79 ±â€¯40 ms vs. 92 ±â€¯48 ms, P = 0.07). A high scar tissue burden was more pronounced in non-responders (1.4 ±â€¯0.6 vs. 1.0 ±â€¯0.5, P = 0.01). CONCLUSIONS: LAD in the presence of LBBB is a predictor of poor outcome after CRT. Patients with LBBB and LAD have more scar tissue, hypertrophy and less activation delay.

Early Versus Standard Care Invasive Examination and Treatment of Patients With Non-ST-Segment Elevation Acute Coronary Syndrome.

BACKGROUND: The optimal timing of invasive coronary angiography (ICA) and revascularization in patients with non-ST-segment elevation acute coronary syndrome is not well defined. We tested the hypothesis that a strategy of very early ICA and possible revascularization within 12 hours of diagnosis is superior to an invasive strategy performed within 48 to 72 hours in terms of clinical outcomes. METHODS: Patients admitted with clinical suspicion of non-ST-segment elevation acute coronary syndrome in the Capital Region of Copenhagen, Denmark, were screened for inclusion in the VERDICT trial (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography) ( ClinicalTrials.gov NCT02061891). Patients with ECG changes indicating new ischemia or elevated troponin, in whom ICA was clinically indicated and deemed logistically feasible within 12 hours, were randomized 1:1 to ICA within 12 hours or standard invasive care within 48 to 72 hours. The primary end point was a combination of all-cause death, nonfatal recurrent myocardial infarction, hospital admission for refractory myocardial ischemia, or hospital admission for heart failure. RESULTS: A total of 2147 patients were randomized; 1075 patients allocated to very early invasive evaluation had ICA performed at a median of 4.7 hours after randomization, whereas 1072 patients assigned to standard invasive care had ICA performed 61.6 hours after randomization. Among patients with significant coronary artery disease identified by ICA, coronary revascularization was performed in 88.4% (very early ICA) and 83.1% (standard invasive care). Within a median follow-up time of 4.3 (interquartile range, 4.1-4.4) years, the primary end point occurred in 296 (27.5%) of participants in the very early ICA group and 316 (29.5%) in the standard care group (hazard ratio, 0.92; 95% CI, 0.78-1.08). Among patients with a GRACE risk score (Global Registry of Acute Coronary Events) >140, a very early invasive treatment strategy improved the primary outcome compared with the standard invasive treatment (hazard ratio, 0.81; 95% CI, 0.67-1.01; P value for interaction=0.023). CONCLUSIONS: A strategy of very early invasive coronary evaluation does not improve overall long-term clinical outcome compared with an invasive strategy conducted within 2 to 3 days in patients with non-ST-segment elevation acute coronary syndrome. However, in patients with the highest risk, very early invasive therapy improves long-term outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02061891.

Interlead electrical delays and scar tissue: Response to cardiac resynchronization therapy in patients with ischemic cardiomyopathy.

BACKGROUND: The importance of interlead electrical delays (IEDs) in the presence of scar tissue for response to cardiac resynchronization therapy (CRT) in patients with ischemic cardiomyopathy is poorly described. METHODS: Sixty-eight CRT patients with ischemic cardiomyopathy and left bundle branch block were included. IEDs, the time between sensing of native impulse at the RV lead and LV lead, were measured at implantation and after 8 months. Magnetic resonance imaging was used for assessment of scar tissue. Echocardiographic response was defined as ≥ 15% decrease in left ventricular end-systolic volume. New York Heart Association (NYHA) class, Minnesota Living with Heart Failure Questionnaire, and 6-minute walk-test were used to assess clinical response. RESULTS: A total of 44 patients (65 %) were responders to CRT. At implantation, IEDs were significantly longer among responders compared to nonresponders (RV-LV-IED: 87 ms ± 33 ms vs 65 ms ± 47 ms, P < 0.05), most evident in patients with QRS < 150 ms. Responders had less myocardial scar tissue than nonresponders (1 ± 0.5 vs 1.4 ± 0.6, P = 0.01). However, in the multivariate model including QRS duration and scar tissue, IEDs were independently associated with LV remodeling after CRT: odds ratio 3.99 [95% confidence interval 1.02-15.7] (P = 0.04). During the course of treatment, no changes were observed in IEDs among echocardiographic responders. CONCLUSION: RV-LV-IED was an independent marker of response in CRT patients with ischemic cardiomyopathy even in the presence of scar tissue and may be particularly useful in patients with QRS < 150 ms. CRT did not influence this measurement over time.

Index of contractile asymmetry improves patient selection for CRT: a proof-of-concept study.

BACKGROUND: Nearly one-third of heart failure (HF) patients do not respond to cardiac resynchronization therapy (CRT) despite having left bundle branch block (LBBB). The aim of the study was to investigate a novel method of quantifying left ventricular (LV) contractile asymmetry in HF. METHODS: Patients with HF and LBBB undergoing CRT (n = 89, 37.1% females, 68 ± 9 years, ischemic etiology in 61%, LV ejection fraction 27.1 ± 7.1%) were analyzed. LV longitudinal systolic strain rate values were extracted from curved anatomical M-mode plots of standard long-axis 2D-echocardiography images and cubic spline interpolation was used to generate a 3D-phantom. Index of contractile asymmetry (ICA) was calculated based on standard deviation of differences in strain rate of opposing walls. Average ICA was individually assessed pairwise in 12 opposing 30-degree LV sectors. Reduction in LV end-systolic volume (ESV) ≥15% after 6 months was considered as positive response to CRT. RESULTS: CRT response was found in 66 (74.2%) patients. Responders with both ischemic and non-ischemic cardiomyopathy had a higher and more extensive contractile asymmetry at baseline and achieved a greater ICA reduction after CRT than non-responders. Higher baseline ICA predicted higher degree and wider extent of ICA improvement. Also, both ICA at baseline and reduction of ICA correlated with the degree of ESV reduction after CRT. CONCLUSIONS: Quantification of asymmetrical LV activation in 3D by ICA provides valuable insights into LV contraction in case of LBBB and is a promising tool for improved patient selection for CRT.

Safety profile and utility of treadmill exercise in patients with high-gradient hypertrophic cardiomyopathy.

BACKGROUND: Exercise echocardiography in the evaluation of hypertrophic cardiomyopathy (HCM) provides valuable information for risk stratification, selection of optimal treatment, and prognostication. However, HCM patients with left ventricular outflow tract gradients ≥30mm Hg are often excluded from exercise testing because of safety considerations. We examined the safety and utility of exercise testing in patients with high-gradient HCM. METHODS: We evaluated clinical characteristics, hemodynamics, and imaging variables in 499 consecutive patients with HCM who performed 959 exercise tests. Patients were divided based on peak left ventricular outflow tract gradients using a 30-mm Hg threshold into the following: obstructive (n=152), labile-obstructive (n=178), and nonobstructive (n=169) groups. RESULTS: There were no deaths during exercise testing. We noted 20 complications (2.1% of tests) including 3 serious ventricular arrhythmias (0.3% of tests). There was no difference in complication rate between groups. Patients with obstructive HCM had a higher frequency of abnormal blood pressure response (obstructive: 53% vs labile: obstructive: 41% and nonobstructive: 37%; P=.008). Obstructive patients also displayed a lower work capacity (obstructive: 8.4±3.4 vs labile obstructive: 10.9±4.2 and nonobstructive: 10.2±4.0, metabolic equivalent; P<.001). Exercise testing provided incremental information regarding sudden cardiac death risk in 19% of patients with high-gradient HCM, and we found a poor correlation between patient-reported functional class and work capacity. CONCLUSION: Our results suggest that exercise testing in HCM is safe, and serious adverse events are rare. Although numbers are limited, exercise testing in high-gradient HCM appears to confer no significant additional safety hazard in our selected cohort and could potentially provide valuable information.

Myocardial perfusion 320-row multidetector computed tomography-guided treatment strategy for the clinical management of patients with recent acute-onset chest pain: Design of the CArdiac cT in the treatment of acute CHest pain (CATCH)-2 randomized controlled trial.

AIMS: Patients admitted with chest pain are a diagnostic challenge because the majority does not have coronary artery disease (CAD). Assessment of CAD with coronary computed tomography angiography (CCTA) is safe, cost-effective, and accurate, albeit with a modest specificity. Stress myocardial computed tomography perfusion (CTP) has been shown to increase the specificity when added to CCTA, without lowering the sensitivity. This article describes the design of a randomized controlled trial, CATCH-2, comparing a clinical diagnostic management strategy of CCTA alone against CCTA in combination with CTP. METHODS: Patients with acute-onset chest pain older than 50 years and with at least one cardiovascular risk factor for CAD are being prospectively enrolled to this study from 6 different clinical sites since October 2013. A total of 600 patients will be included. Patients are randomized 1:1 to clinical management based on CCTA or on CCTA in combination with CTP, determining the need for further testing with invasive coronary angiography including measurement of the fractional flow reserve in vessels with coronary artery lesions. Patients are scanned with a 320-row multidetector computed tomography scanner. Decisions to revascularize the patients are taken by the invasive cardiologist independently of the study allocation. The primary end point is the frequency of revascularization. Secondary end points of clinical outcome are also recorded. DISCUSSION: The CATCH-2 will determine whether CCTA in combination with CTP is diagnostically superior to CCTA alone in the management of patients with acute-onset chest pain.

Ratio of early transmitral inflow velocity to early diastolic strain rate predicts atrial fibrillation following acute myocardial infarction.

The ratio of early transmitral filling velocity to early diastolic strain rate (E/SRe) has been proposed as a new non-invasive measurement of left ventricular filling pressure. We aimed to investigate the ability of E/SRe to predict atrial fibrillation (AF) after ST-elevation myocardial infarction (STEMI). This was a prospective cohort study of patients (n = 369) with STEMI. Patients underwent an echocardiographic examination a median of two days after pPCI. By echocardiography, transmitral early filling velocity (E) was measured by pulsed-wave Doppler, and early diastolic strain rate (SRe) was measured by speckle tracking of the left ventricle. E was indexed to SRe and the early myocardial relaxation velocity (e') to obtain the E/SRe and E/e', respectively. The endpoint was new-onset AF. During follow-up (median 5.6 years, IQR: 5.0-6.1 years), 23 (6%) of the 369 patients developed AF. In unadjusted analyses, both E/SRe and E/e' were significantly associated with AF [E/SRe: HR = 1.06; (1.03-1.10); p < 0.001, per 10 increase] and [E/e': HR = 1.11 (1.05-1.17); p < 0.001, per 1 increase] and had equal Harrell's C-statistic of 0.71. However, only E/SRe remained an independent predictor after multivariable adjustments for clinical and echocardiographic parameters [E/SRe: HR = 1.06 (1.00-1.11); p = 0.044, per 10 increase]. E/SRe was further significantly associated with AF in patients with E/e' < 14 HR = 1.09 (1.01-1.17); p = 0.030, per 10 increase), also after multivariable adjustments. E/SRe is an independent predictor of AF in STEMI patients, even in subjects with seemingly normal filling pressure.

Left bundle-branch block: the relationship between electrocardiogram electrical activation and echocardiography mechanical contraction.

BACKGROUND: The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently been independently published for both ECG and echocardiography. The relationship between the 2 modalities and the relation to cardiac resynchronization therapy (CRT) response was investigated. METHODS: Sixty-six patients with LBBB by conventional criteria had a standard 12-lead ECG and 2-dimensional strain echocardiography performed before CRT implantation. Criteria for LBBB by echocardiography included early termination of contraction in one wall and prestretch and late contraction in opposing wall(s). New strict criteria by ECG included QRS duration ≥140 ms (men) or 130 ms (women), QS or rS in leads V1 and V2, and mid-QRS notching or slurring in ≥2 of leads V1, V2, V5, V6, I, and aVL. Response was defined as >15% decrease in left ventricular end-systolic volume after 6 months. RESULTS: In 64 of 66 patients, ECG analysis was possible. Echo and ECG readings for LBBB presence were concordant in 54 (84%) of 64. Thirty-seven (82%) of 45 patients with LBBB by strict ECG criteria responded to CRT, whereas only 4 (21%) of the 19 patients without LBBB responded (sensitivity 90% and specificity 65%). Thirty-six (95%) of 38 patients with concordance for the presence of LBBB responded to CRT. In patients with concordance for the absence of LBBB, 15 (94%) of 16 did not respond. CONCLUSION: For the first time, a close relation has been demonstrated between electrical activation by ECG and mechanical contraction by echocardiography. These findings may help identify CRT candidates.

Left bundle branch block without a typical contraction pattern is associated with increased risk of ventricular arrhythmias in cardiac resynchronization therapy patients.

Cardiac resynchronization therapy (CRT) reduces the risk of ventricular arrhythmias (VA) in heart failure (HF) patients with left bundle branch block (LBBB) while the effect is less clear among non-LBBB patients. This study aimed to investigate if absence of LBBB features whether by echocardiography or strict ECG criteria would identify patients at risk of developing VA in a cohort with LBBB according to conventional ECG criteria. Two hundred six CRT candidates were prospectively included from 2 centers. Prior to CRT presence of a typical LBBB contraction pattern was identified using longitudinal strain in the apical 4-chamber view. All preimplantation ECGs were categorized as LBBB or non-LBBB according to Strauss´ strict criteria. Primary end-point was defined as any appropriate antitachycardia pacing (ATP) or shock therapy within 2 years after CRT implantation. A total of 129 (63%) patients had a typical LBBB contraction pattern, while 134 (66%) met the strict ECG criteria. Over 2 years, 45 patients (22%) experienced VA. Absence of a typical LBBB contraction pattern was independently associated with an increased risk of VA (hazard ratio ([HR] 1.89; 95% CI 1.04 to 3.44; p: 0.036). Strict LBBB was not independently associated with the occurrence of VA. Fulfilling neither strict ECG nor echocardiographic criteria for LBBB was associated with a 3.3-fold increase in risk of VA ([HR] 3.34; 95% CI 1.75 to 6.94; (p < 0.001). The risk of VA was almost 2-fold higher if a typical LBBB contraction pattern was absent prior to CRT.

The role of local voltage potentials in outflow tract ectopy.

AIMS: Discrete, fragmented, local voltage potentials (LVPs) have been observed in electrograms recorded at the ablation site in patients undergoing radiofrequency ablation for arrhythmias originating in both the right and left ventricular outflow tract; however, the incidence and the significance of the LVP with respect to arrhythmogenesis is uncertain. METHODS AND RESULTS: We studied 25 patients with outflow tract arrhythmias referred for radiofrequency catheter ablation and recorded high-amplified intracardiac electrograms close to the site of origin of the arrhythmia. Ten patients undergoing ablation for supraventricular arrhythmias served as controls. During sinus rhythm, LVPs were recorded in 24 of the 25 patients, 10-85 ms (41 +/- 19 ms) after the onset of the QRS complex, duration 33 +/- 11 ms, voltage 2.0 +/- 1.5 mV. The same potential was recorded 10-52 ms (mean 37 +/- 11 ms) prior to the V potential in the ventricular premature beats. In 10 patients, ventricular parasystole was suggested by varying coupling intervals >100 ms, and fusion beats allowing for the estimation of the least common denominator of R-R intervals. In 23 of the 25 patients, the 12-lead electrocardiogram (ECG) and intracardiac contact mapping located the arrhythmias to an area of 3-4 cm(2) in the septal region of the right ventricular outflow tract; in two patients, the site of origin was in the left coronary cusp. Radiofrequency ablation carried out in 24 of the 25 patients was successful in 21 patients, and after successful ablation, the LVP could still be recorded in all these 21 patients. The LVP was not present in 10 controls. CONCLUSION: Local potentials are recorded close to the site of origin of ventricular ectopy in >90% of patients with idiopathic outflow tract ectopy and imply successful ablation. The potentials may reflect an area of depressed conductivity known to be a prerequisite for experimental ventricular ectopy including parasystole.

Two-dimensional global longitudinal strain is superior to left ventricular ejection fraction in prediction of outcome in patients with left-sided infective endocarditis.

BACKGROUND: Impaired cardiac function is the main predictor of poor outcome in infective endocarditis (IE). Global longitudinal strain (GLS) derived from two-dimensional strain echocardiography has proven superior in prediction of long-term outcome as compared to left ventricular ejection fraction (LVEF) in valvular disease and heart failure in general. Whether measurements of cardiac deformation can predict survival in patients with IE has not previously been investigated. METHODS: The study included consecutive patients with Duke definite IE who underwent transthoracic and transesophageal echocardiography within 7 days. Clinical and echocardiographic markers associated with 1-year survival were identified using a Cox-proportional hazards model that included propensity adjustment for surgery. Reclassification statistics including receiver operating characteristic curves and net reclassification improvement were applied to LVEF and GLS, respectively. RESULTS: A cohort of 190 patients met eligibility criteria. LVEF and GLS were both prognostic markers of mortality. Independent markers of 1-year mortality were S. aureus IE (HR:2.02; 95%CI 1.11-5.72, p = .022), diabetes (HR:2.05; 95%CI 1.12-3.75, p = .020), embolic stroke (HR:3.95; 95%CI 1.93-8.10, p < .001) and LVEF<45% (HR: 3.02; 95% CI 1.70-5.38, p < .001), GLS> -15.4% (HR:2.95; 95%CI 1.52-5.72, p < .001). Adding LVEF<45% to a model with known risk factors of IE did not significantly improve risk classification, whereas addition of GLS to the model resulted in significant increase (AUC = 0.763, p < .001). CONCLUSIONS: When treatment was taken into account, LVEF<45% and GLS > -15.4% were both associated with adverse long-term outcome in left-sided IE. GLS >-15.4 % was significantly associated with 1-year mortality in the multivariate analysis. Further, GLS was superior to LVEF in risk prediction and risk discrimination of long-term outcome in patients with left-sided IE.

Whole-genome sequencing of bloodstream Staphylococcus aureus isolates does not distinguish bacteraemia from endocarditis.

Most Staphylococcus aureus isolates can cause invasive disease given the right circumstances, but it is unknown if some isolates are more likely to cause severe infections than others. S. aureus bloodstream isolates from 120 patients with definite infective endocarditis and 121 with S. aureus bacteraemia without infective endocarditis underwent whole-genome sequencing. Genome-wide association analysis was performed using a variety of bioinformatics approaches including SNP analysis, accessory genome analysis and k-mer based analysis. Core and accessory genome analyses found no association with either of the two clinical groups. In this study, the genome sequences of S. aureus bloodstream isolates did not discriminate between bacteraemia and infective endocarditis. Based on our study and the current literature, it is not convincing that a specific S. aureus genotype is clearly associated to infective endocarditis in patients with S. aureus bacteraemia.

Early myocardial impairment in type 1 diabetes patients without known heart disease assessed with tissue Doppler echocardiography: The Thousand & 1 study.

PURPOSE: Cardiovascular disease is the most common cause of mortality in type 1 diabetes; patients with albuminuria are at greatest risk. We investigated myocardial function and premature myocardial impairment in type 1 diabetes patients with and without albuminuria compared to controls. METHODS: This study included a cross-sectional survey of 1093 type 1 diabetes patients from Steno Diabetes Center and 200 healthy controls. Conventional and tissue Doppler echocardiographic measurements were analysed in multivariable models in normoalbuminuria (n = 760), microalbuminuria (n = 227) and macroalbuminuria (n = 106). Investigators were blinded to degree of albuminuria. RESULTS: For the type 1 diabetes patients, mean age was 49.6 years, 53% were men and mean diabetes duration was 25.5 years. In multivariable models systolic velocity s' did not differ between type 1 diabetes patients with normoalbuminuria and controls (ß-coefficient [95% confidence interval]: -0.17 [-0.41; 0.08], p = 0.19), but was impaired between controls and microalbuminuria (-0.53 [-0.84; -0.23], p = 0.001) and macroalbuminuria (-0.59 [-0.96; -0.22], p = 0.002). Diastolic measurements (e', a', e'/a', and E/e') were all significantly impaired in type 1 diabetes, for example, e'/a': normoalbuminuria, microalbuminuria and macroalbuminuria versus controls: -0.38 [-0.52; -0.23], p < 0.001; -0.49 [-0.67; -0.32], p < 0.001; and -0.81 [-1.03; -0.59], p < 0.001. In age-related analyses, myocardial impairment occurred prematurely in type 1 diabetes compared to controls (e.g. E/e' = 8; 9.2 years [normoalbuminuria], 17.3 years [microalbuminuria] and 41.4 years [macroalbuminuria] prematurely, respectively). CONCLUSION: In type 1 diabetes patients with albuminuria, both systolic and diastolic functions are impaired, whereas in patients without albuminuria only diastolic function is affected. Myocardial impairment is detectable many years prematurely in type 1 diabetes, especially in patients with albuminuria.

Staphylococcus aureus endocarditis with fast development of aortic root abscess despite relevant antibiotics.

We present a case of Staphylococcus aureus endocarditis in which a large abscess was formed in only 4 days, despite specific intravenous antibiotics and only few vague signs of disease progression. Our case seems to be the first to show echocardiographic documentation of how quickly an intracardiac abscess can develop despite relevant antibiotics. Clinically, the patient is remarkably unaffected, and thus even small signs of progression should lead to considerations about repeating the diagnostic imaging workup. This case illustrates how aggressive an infection S. aureus endocarditis may be, and therefore it should be treated by an experienced team with easy access to both transthoracic and transesophageal echocardiography.

Myocardial performance is reduced immediately prior to ventricular ectopy.

BACKGROUND: We recently demonstrated local voltage potentials indicating conduction impairment and block in the sinus beats preceding ventricular premature beats (VPBs) originating in the ventricular outflow tracts. OBJECTIVE: The purpose of this study was to test the hypothesis that impairment of impulse conduction would also lead to changes in the contractile performance of sinus beats preceding ventricular ectopy using Tissue Doppler echocardiography. METHODS: Twenty-three consecutive patients with VPBs were examined in the apical 4-chamber view with a frame rate of 150 Hz (GE VIVID VII). Eleven patients had no structural heart disease, 5 had dilated cardiomyopathy, 4 had ischemic heart disease, 2 had arrhythmogenic right ventricular dysplasia, and 1 had aortic stenosis. The ectopy originated in the ventricular outflow tracts in 15 patients and in the left ventricle 8. Eleven of the patients underwent radiofrequency ablation of the VPBs. RESULTS: Tissue Doppler imaging demonstrated a highly statistically significant decrease in myocardial performance in the last sinus beat before the VPB compared to earlier sinus beats. Thus, ejection time (time to peak end-systolic contraction) and peak systolic velocity shortened significantly (P <.001 for both) with a subsequent reduction in systolic shortening (end-systolic displacement; P <.001). CONCLUSION: Ventricular ectopy is preceded by a significant decrease in myocardial performance in the last sinus beat preceding VPBs as observed in consecutive patients with a broad variety of heart conditions pointing to a mutual underlying electrical mechanism (ie, localized conduction block confined to an area surrounding the ectopic pacemaker).

Long-term outcome of percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: a Scandinavian multicenter study.

BACKGROUND: Single-center reports on percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy have shown considerable differences in outcome. METHODS AND RESULTS: We report the long-term outcome of 313 PTSMA procedures performed in 279 patients with hypertrophic obstructive cardiomyopathy aged 59±14 years from 1999 to 2010 in 4 Scandinavian centers. Sixty-nine percent of patients had ≥1 comorbidity at baseline. The median (interquartile range) of left ventricular outflow tract gradient at rest was reduced from 58 mm Hg (34 to 89 mm Hg) at baseline to 12 mm Hg (8 to 24 mm Hg) at 1-year (P<0.001) and during Valsalva maneuver from 93 mm Hg (70 to 140 mm Hg) to 21 mm Hg (11 to 42 mm Hg) (P<0.001). The proportion of patients with syncope was reduced from 18% to 2% (P<0.001), and the proportion in New York Heart Association class III/IV was reduced from 94% to 21% (P<0.001). All treatment effects remained stable during the follow-up. New York Heart Association class III/IV at the most recent follow-up (2.9±2.6 years) was associated with diabetes mellitus (P=0.03), chronic obstructive pulmonary disease (P=0.02), and valve disease unrelated to hypertrophic cardiomyopathy (P<0.01). In-hospital mortality was 0.3%. The 1-, 5- and 10-year survival rates were 97%, 87%, and 67%, respectively (P=0.06 versus an age- and sex-matched background population) in all patients and 99%, 94%, and 88%, respectively (P=0.12) in patients aged <60 years (48±9 years, n=141). Age (hazard ratio, 1.07; 95% CI, 1.03 to 1.1) was the only predictor of survival. CONCLUSIONS: In this multicenter study, the in-hospital mortality after PTSMA was low despite considerable comorbidities. The hemodynamic and symptomatic effects were sustained long term. The long-term symptomatic outcome was associated with baseline comorbidities. The 10-year survival rate was comparable to that in an age- and sex-matched background population, and age was the only predictor of survival.

Metformin is associated with improved left ventricular diastolic function measured by tissue Doppler imaging in patients with diabetes.

OBJECTIVE: To examine the association between selected glucose-lowering medications and left ventricular (LV) diastolic function in patients with diabetes. DESIGN: Retrospective cohort study (years 2005-2008). METHODS: Echocardiograms of 242 patients with diabetes undergoing coronary angiography were analyzed. All patients had an LV ejection fraction (LVEF) ≥20% and were without atrial fibrillation, bundle branch block, valvular disease, or cardiac pacemaker. Patients were grouped according to the use of metformin (n=56), sulfonylureas (n=43), insulin (n=61), and combination treatment (n=82). RESULTS: Mean age (66±10 years) and mean LVEF (45±11%) were similar across the groups. Mean isovolumic relaxation time (IVRT) was 66±31, 79±42, 69±23, and 66±29 ms in metformin, sulfonylureas, insulin, and combination treatment groups respectively (P=0.4). Mean early diastolic longitudinal tissue velocity (e') was 5.3±1.6, 4.6±1.6, 5.3±1.8, and 5.4±1.7 cm/s in metformin, sulfonylureas, insulin, and combination treatment groups (P=0.04). In adjusted linear regression models, the use of metformin was associated with a shorter IVRT (parameter estimate -9.9 ms, P=0.049) and higher e' (parameter estimate +0.52 cm/s, P=0.03), compared with no use of metformin. The effects of metformin were not altered by concomitant use of sulfonylureas or insulin (P for interactions >0.4). CONCLUSIONS: The use of metformin is associated with improved LV relaxation, as compared with no use of metformin.