Christina Ocklenburg

Impact of left ventricular lead position on the efficacy of cardiac resynchronisation therapy: a two-dimensional strain echocardiography study.

Background: Definition of the optimal left ventricular (LV) lead position in cardiac resynchronisation therapy (CRT) is desirable. Objective: To define the optimal LV lead position in CRT and assess the effectiveness of CRT depending on the LV lead position using new myocardial deformation imaging. Methods: Myocardial deformation imaging based on tracking of acoustic tissue pixels in two-dimensional echocardiographic images (EchoPAC, GE ultrasound) was performed in 47 patients with heart failure at baseline and during CRT. In a 36-segment LV model the segment with the latest peak systolic circumferential strain before CRT was determined. The segment with maximal temporal difference in peak systolic circumferential strain on CRT compared with before CRT was assumed to be the LV lead position. The optimal LV lead position was defined as concurrence or immediate neighbouring of the segment with the latest contraction before CRT and those with assumed LV lead location. Results: 25 patients had optimal and 22 non-optimal LV lead positions. Before CRT, the LV ejection fraction (EF) and peak oxygen consumption (Vo2max) were similar in patients with optimal and non-optimal LV lead positions (mean (SD) EF = 31.4 (6.1)% vs 30.3 (6.5)% and Vo2max = 14.2 (1.8) vs 14.0 (2.1) ml/min/kg, respectively). At 3 months on CRT, EF increased by 9 (2)% vs 5 (3)% and Vo2max by 2.0 (0.8) vs 1.1 (0.5) ml/min/kg in the optimal vs non-optimal LV lead position groups, respectively (both p<0.001). Conclusions: Concordance of the LV lead site and location of the latest systolic contraction before CRT results in greater improvement in EF and cardiopulmonary workload than the non-optimal LV lead position.

Myocardial Deformation Imaging Based on Ultrasonic Pixel Tracking to Identify Reversible Myocardial Dysfunction

OBJECTIVES This study evaluated the predictive value of myocardial deformation imaging for improvement in cardiac function after revascularization therapy in comparison with contrast-enhanced cardiac magnetic resonance imaging (ceMRI). BACKGROUND Myocardial deformation imaging allows analysis of myocardial viability in ischemic left ventricular dysfunction. METHODS In 53 patients with ischemic left ventricular dysfunction, myocardial viability was assessed using pixel-tracking-derived myocardial deformation imaging and ceMRI to predict recovery of function at 9 +/- 2 months follow-up. For each left ventricular segment in a 16-segment model, peak systolic radial strain was determined from parasternal 2-dimensional echocardiographic views using an automatic frame-by-frame tracking system of natural acoustic echocardiographic markers (EchoPAC, GE Ultrasound, Horton, Norway), and the relative extent of hyperenhancement using ceMRI. RESULTS Of 463 segments with abnormal baseline function, 227 showed regional recovery. Compared with segments showing functional improvement, those that failed to recover had lower peak radial strain (15.2 +/- 7.5% vs. 22.6 +/- 6.3%; p < 0.001) and a greater extent of hyperenhancement (56 +/- 29% vs. 14 +/- 17%; p < 0.001). Using a cutoff of 17.2% for peak systolic radial strain, functional recovery could be predicted with high accuracy (sensitivity 70.2%, specificity 85.1%, area under the curve 0.859, 95% confidence interval 0.825 to 0.893). The predictive value was similar to that of hyperenhancement by ceMRI (sensitivity 71.6%, specificity 92.1%, area under the curve 0.874, 95% confidence interval 0.840 to 0.901, at a cutoff of 43% hyperenhancement). CONCLUSIONS Myocardial deformation imaging based on frame-to-frame tracking of acoustic markers in 2-dimensional echocardiographic images is a powerful novel modality to identify reversible myocardial dysfunction.

Impact of infarct transmurality on layer-specific impairment of myocardial function: a myocardial deformation imaging study.

AIMS To evaluate deformation parameters of an endocardial, mid-myocardial, and epicardial myocardial layer in different transmurality of myocardial infarction and assess whether layer-specific deformation analysis allows definition of infarct transmurality. METHODS AND RESULTS Fifty-six patients (mean age 55 +/- 9 years, 38 men) with chronic ischaemic left ventricular (LV) dysfunction underwent two-dimensional echocardiography and contrast-enhanced magnetic resonance imaging (ceMRI). The extent of myocardial infarction was determined as relative amount of hyperenhancement by ceMRI in a 16-segment LV model (0%, no infarction; 1-50%, non-transmural infarction; 51-100%, transmural infarction). On the basis of two-dimensional echocardiographic parasternal short-axis views peak systolic circumferential strain was determined for the total wall thickness and for each of three myocardial layers (endocardial, mid-myocardial, and epicardial) using an automatic frame-by-frame tracking system of acoustic echocardiographic markers (EchoPAC, GE Ultrasound). In non-transmural infarction impairment of circumferential strain was greater in the endocardial than the epicardial layer, relative reduction compared with control segments, 45% vs. 28% (P < 0.001), respectively. In transmural infarction additional impairment of circumferential strain was greater in the epicardial than the endocardial layer, relative reduction compared with non-transmural infarction 29% vs. 7% (P < 0.001), respectively. Endocardial layer circumferential strain allowed distinction of non-transmural vs. no infarction with higher accuracy than total wall thickness strain [area under the curve (AUC) 0.842 vs. 0.774, respectively, P = 0.001]. Epicardial layer circumferential strain allowed distinction of transmural from non-transmural infarction with higher accuracy than total wall thickness strain (AUC 0.819 vs. 0.762, respectively, P = 0.005). CONCLUSION Non-transmural infarction results in greater functional impairment of the endocardial than of the epicardial myocardial layer. In transmural infarction both layers are affected similarly compared with controls. A layer-specific analysis of myocardial deformation allows accurate discrimination between different transmurality categories of myocardial infarction.

Epidemiology of invasive Streptococcus pyogenes disease in Germany during 2003–2007

A nationwide laboratory-based surveillance study of invasive Streptococcus pyogenes infections was conducted in Germany. Invasive isolates (n=586) were obtained between 2003 and 2007. Most isolates were obtained from blood (53.9%) or skin lesions (17.6%). The most common emm types were emm 1 (30.5%), emm 28 (18.3%) and emm 3 (9.6%). Overall, speA was positive in 45.9%, speC in 44.7% and ssa in 14.8% of isolates. SpeA was common in emm type 1 (100%) and emm type 3 (96.4%), whereas speC was often observed in emm type 28 (93.5%). The most frequent clinical manifestations included sepsis (40.1%), necrotizing fasciitis (20.8%) and streptococcal toxic shock syndrome (16.6%). All isolates were susceptible to penicillin G, cefotaxime and levofloxacin. Tetracycline shows the highest rate of resistant or intermediate isolates with 11.6%, followed by clarithromycin (5.5%) and clindamycin (1.2%). The most prominent trend is the reduction of tetracycline-nonsusceptible isolates from 18.6% in 2003 to 8.9% in 2007.

Jugular versus subclavian totally implantable access ports: catheter position, complications and intrainterventional pain perception.

PURPOSE To determine the safest and most tolerable method for totally implantable access ports (TIAPs) particularly in regard to patients pain perception and catheter-related complications. MATERIALS AND METHODS From January 2007 to October 2008 a subcutaneous TIAP (Bardport, Bard Access System, UT, USA) was implanted in 138 oncological patients (60 male, 78 female; 18-85 years old; mean age of 56 ± 6 years) by experienced interventional radiologists. 94 TIAP were implanted through the subclavian vein (subclavian group) and 44 TIAP were implanted through the internal jugular vein (jugular group). Intrainterventional pain perception (visual analogue scale from 1 to 10), postinterventional catheter tip migration and radiation dose were documented for each method and implantation side and differences were compared with Wilcoxon t-test. For ordinal variables, comparison of two groups was performed with the Fishers exact test. RESULTS No severe periinterventional complication occurred. Inadvertent arterial punctures without serious consequences were reported in one case for the jugular group versus four cases in the subclavian group. Significantly (p<0.05) lower pain perception, radiation dose and tip migration rate were observed in the jugular group. Catheter occlusions occurred in 4% (n=4) of the subclavian group versus 2% (n=1) of the jugular group. The corresponding values for vein thrombosis and catheter dislocation were 3% (n=3) and 1% (n=1) in the subclavian group, while none of those complications occurred in the jugular group. CONCLUSION Both techniques, the TIAP implantation via fluoroscopy-guided subclavian vein puncture and via ultrasound-guided jugular vein puncture, are feasible and safe. Regarding intrainterventional pain perception, radiation dose, postinterventional catheter tip position and port function the jugular vein puncture under ultrasound guidance seems to be advantageous.

Impact of Systolic and Diastolic Deformation Indexes Assessed by Strain-Encoded Imaging to Predict Persistent Severe Myocardial Dysfunction in Patients After Acute Myocardial Infarction at Follow-Up

OBJECTIVES This study evaluated the value of systolic and diastolic deformation indexes determined by strain-encoded imaging to predict persistent severe dysfunction at follow-up in patients after reperfused acute myocardial infarction (AMI) in comparison with late gadolinium enhancement (LGE). BACKGROUND Animal studies suggest that regional diastolic function provides information about myocardial viability after AMI. However, data in humans are sparse. METHODS Twenty-six patients underwent magnetic resonance imaging 3 ± 1 days after successfully reperfused ST-segment elevation myocardial infarction and at a follow-up of 6 months. Cine, strain-encoded, and LGE images were acquired. Peak systolic circumferential strain (E(cc)) and early diastolic strain rate (E(cc)/s) were calculated for each segment at baseline and at follow-up. A cutoff E(cc) value of -9% was used to define severe dysfunction at follow-up. RESULTS A total of 312 segments were analyzed; 119 segments showed abnormal baseline function. Thirty-five segments showed severe dysfunction at follow-up, which was defined as E(cc) at follow-up <9%. The area under the curve for E(cc)/s was 0.82 (95% confidence interval [CI]: 0.72 to 0.89), for E(cc) 0.74 (95% CI: 0.64 to 0.83), and for LGE 0.85 (95% CI: 0.77 to 0.92). A comparison of receiver-operating characteristic curves demonstrates that LGE is not significantly different than E(cc)/s but is significantly different than E(cc) (p = 0.32 vs. p < 0.05) for prediction of severe dysfunction at follow-up. CONCLUSIONS Regional diastolic function provides similar accuracy to predict persistent severe dysfunction at follow-up to LGE and is superior to regional systolic function in patients after AMI. Diastolic deformation indexes may serve as a new parameter for assessment of viability in patients after AMI. (SENC in AMI Study; NCT00752713).

Association of serotypes of Streptococcus pneumoniae with age in invasive pneumococcal disease

ABSTRACT A total of 7,764 isolates from patients with invasive pneumococcal disease (IPD) were collected from 1992 to June 2006. Data on serotypes were available for 5,022 isolates (64.7% of all invasive isolates). Some 54.0% of the isolates originated from adults ≥16 years of age, and 46.0% were from children <16 years of age. The leading serotypes were 14, 23F, 1, 6B, 7F, 3, and 4. The serotypes significantly more common in children were 14, 6B, 19F, and 18C, while among adults, serotypes 3 and 4 were predominant. Serotype 7F was statistically more prevalent among children <4 months old than among the other age groups. Among children aged ≥4 months and <1 year, serotype 19F occurred statistically more frequently; and among children aged ≥1 year to <5 years, serotypes 14, 6B, and 18C were overrepresented. The serotypes predominantly affecting patients younger than the remaining collective of patients were 14, 6B, 19F, and 18C, while patients with IPD caused by serotypes 3, 4, and 9V were older than the collective, on average.

Strain-Encoded MRI for Evaluation of Left Ventricular Function and Transmurality in Acute Myocardial Infarction

Background—Strain-encoded imaging (SENC) is a new technique for myocardial deformation analysis in cardiac MRI. The aim of the study was, therefore, to evaluate whether myocardial deformation imaging performed by SENC allows for quantification of regional left ventricular function and is related to transmurality states of infarcted tissue in patients with acute myocardial infarction. Methods and Results—Cardiac MRI was performed in 38 patients with acute myocardial infarction 3±1 days after successful reperfusion using a clinical 1.5-T MRI scanner. Ten healthy volunteers served as controls. SENC is a technique that directly measures peak circumferential strain from long-axis views and peak longitudinal strain from short-axis views. Measurements were obtained for each segment in a modified 17-segment model. Wall motion and infarcted tissue were evaluated semiquantitatively from steady-state free-precession cine sequences and contrast-enhanced MR images and were then related to myocardial strain. Comparison of peak circumferential strain assessed by SENC and MR tagging was performed. In total, 456 segments were analyzed. Peak circumferential and longitudinal strain calculated from SENC images was significantly different in regions defined as normokinetic, hypokinetic, or akinetic (P<0.001). A cutoff peak systolic circumferential strain value of −10% differentiated nontransmural from transmural infarcted myocardium, with a sensitivity of 97% and a specificity of 94%. Strain analysis of SENC and MR tagging correlated well (r=0.76) with narrow limits of agreement (−9.9% to 8.5%). Conclusions—SENC provides rapid and objective quantification of regional myocardial function and allows discrimination between different transmurality states in patients with acute myocardial infarction.

Dependency of cardiac resynchronization therapy on myocardial viability at the LV lead position.

OBJECTIVES This study sought to analyze the effectiveness of cardiac resynchronization therapy (CRT) related to the viability in the segment of left ventricular (LV) lead position defined by myocardial deformation imaging. BACKGROUND Echocardiographic myocardial deformation analysis allows determination of LV lead position as well as extent of myocardial viability. METHODS Myocardial deformation imaging based on tracking of acoustic markers within 2-dimensional echo images (GE Ultrasound, GE Healthcare, Horton, Norway) was performed in 65 heart failure patients (54 ± 6 years of age, 41 men) before and 12 months after CRT implantation. In a 16-segment model, the LV lead position was defined based on the segmental strain curve with earliest peak strain, whereas the CRT system was programmed to pure LV pacing. Nonviability of a segment (transmural scar formation) was assumed if the peak systolic circumferential strain was >-11.1%. RESULTS In 47 patients, the LV lead was placed in a viable segment, and in 18 patients, it was placed in a nonviable segment. At 12-month follow-up there was greater decrease of LV end-diastolic volumes (58 ± 13 ml vs. 44 ± 12 ml, p = 0.0388) and greater increase of LV ejection fraction (11 ± 4% vs. 5 ± 4%, p = 0.0343) and peak oxygen consumption (2.5 ± 0.9 ml/kg/min vs. 1.7 ± 1.1 ml/kg/min, p = 0.0465) in the viable compared with the nonviable group. The change in LV ejection fraction and the reduction in LV end-diastolic volumes at follow-up correlated to an increasing peak systolic circumferential strain in the segment of the LV pacing lead (r = 0.61, p = 0.0274 and r = 0.64, p = 0.0412, respectively). Considering only patients with ischemic heart disease, differences between viable and nonviable LV lead position group were even greater. CONCLUSIONS Preserved viability in the segment of the CRT LV lead position results in greater LV reverse remodeling and functional benefit at 12-month follow-up. Deformation imaging allows analysis of viability in the LV lead segment.

Strain-Encoded Magnetic Resonance Imaging for Evaluation of Left Ventricular Function and Transmurality in Acute Myocardial Infarction

Background—Strain-encoded imaging (SENC) is a new technique for myocardial deformation analysis in cardiac MRI. The aim of the study was, therefore, to evaluate whether myocardial deformation imaging performed by SENC allows for quantification of regional left ventricular function and is related to transmurality states of infarcted tissue in patients with acute myocardial infarction. Methods and Results—Cardiac MRI was performed in 38 patients with acute myocardial infarction 3±1 days after successful reperfusion using a clinical 1.5-T MRI scanner. Ten healthy volunteers served as controls. SENC is a technique that directly measures peak circumferential strain from long-axis views and peak longitudinal strain from short-axis views. Measurements were obtained for each segment in a modified 17-segment model. Wall motion and infarcted tissue were evaluated semiquantitatively from steady-state free-precession cine sequences and contrast-enhanced MR images and were then related to myocardial strain. Comparison of peak circumferential strain assessed by SENC and MR tagging was performed. In total, 456 segments were analyzed. Peak circumferential and longitudinal strain calculated from SENC images was significantly different in regions defined as normokinetic, hypokinetic, or akinetic (P<0.001). A cutoff peak systolic circumferential strain value of −10% differentiated nontransmural from transmural infarcted myocardium, with a sensitivity of 97% and a specificity of 94%. Strain analysis of SENC and MR tagging correlated well (r=0.76) with narrow limits of agreement (−9.9% to 8.5%). Conclusions—SENC provides rapid and objective quantification of regional myocardial function and allows discrimination between different transmurality states in patients with acute myocardial infarction.