Left atrial endocarditis as a rare complication of mitral valve endocarditis: a clinical case

BACKGROUND

Infective Endocarditis (IE) is considered as a multifaceted problem in every aspect from etiology and presentation to diagnosis and management. Early recognition of this disease and especially its complications, remain a critical task for the cardiologist. Atrial endocarditis is a rare and sometimes unrecognized complication of mitral valve endocarditis.

CASE PRESENTATION

We present a 48 year-old male patient who was admitted to our clinic because of recent onset of malaise, fever, jaundice and peripheral edema. Important physical findings were peripheral stigmata of IE in addition to holosystolic murmur over the left sternal border. Transthoracic and transesophageal echocardiophy revealed a severe eccentric MR due to a flailed posterior mitral valve caused by IE. The presence of atrial septal endocarditis caused by jet streaming was also observed. Blood culture was positive for streptococcus oralis and antibiotic therapy was immediately initiated. Considering the large burden of infective tissue, the patient was planned for an early surgical intervention. A minimally invasive resection of the atrial mass, direct closure of the defect, resection of the diseased portions of mitral leaflets and implantation of a biological mitral valve prosthesis was performed. Intra-operative and histological findings confirmed provisional diagnosis by echocardiography.

CONCLUSIONS

Together with comprehensive echocardiographic evaluation, attention should be placed on mural vegetations and excluded among all cases of mitral valve endocarditis, particularly those with severe eccentric regurgitant jets.

Intra-aortic counterpulsation for hemodynamic support in patients with acute ischemic versus non-ischemic heart failure

BACKGROUND

Intra-aortic counterpulsation (IABP) is frequently applied to provide hemodynamic support in patients with refractory cardiogenic shock (CS) of ischemic and non-ischemic cause. However, clinical data comparing outcomes are lacking for both indications. The purpose of this analysis was to evaluate outcome and safety of IABP support in patients with ischemic and non-ischemic CS and to identify predictors of early mortality in this severely ill patient population.

METHODS AND RESULTS

For the period between 1998 to 2010, data from 489 consecutive patients (age, 67.2 ± 12.2 years; 65.9% male) who had received IABP support for CS at the University Heart Center Jena were retrospectively analyzed. The primary endpoint was overall mortality at 7 and 30 days. Secondary endpoints included the incidence of vascular and neurologic complications as well as long-term survival. Follow-up data on current health status of the patients were acquired either from health insurance records or based on patient and physician interviews. After data compilation, patients were assigned to one of the following subgroups: ST-elevation myocardial infarction (STEMI; n = 368; 75.3%), non-STEMI (n = 75; 15.3%) and congestive heart failure (CHF; n = 46; 9.4%). Of the 489 patients enrolled, 422 (86.4%) were successfully weaned from IABP support. However, a significantly lower proportion of patients were weaned successfully in the STEMI group (n = 310; 84.1%) compared to the other two groups (non-STEMI: n = 70, 92.4%; CHF: n = 45, 97.8%; P=.041). Overall mortality at 30 days was 36.4% (n = 178) and was not significantly different between the subgroups. Significant predictors of 30-day mortality included age >70 years (odds ratio [OR], 16.81; confidence interval [CI], 1.241-227.54), ejection fraction <40% (OR, 36.33; CI, 2.93-451.05) and mechanical ventilation (OR, 12.42; CI, 1.21-127.17). Long-term follow-up was 803 ± 1061 days (range, 0-1380 days), with a long-term survival rate of 38.3%.

CONCLUSION

IABP represents a safe technology for hemodynamic support and is associated with low complication rates. Parameters relating to early mortality include age >70 years, respiratory failure requiring mechanical ventilation, and left ventricular function <40%, which represent an additional risk of death. However, the etiology of CS had no effect on mortality in this analysis. This observation should encourage physicians to apply IABP for hemodynamic support in patients with nonischemic left ventricular failure.

Macrophage migration inhibitory factor is elevated in obese adolescents

OBJECTIVES

The prevalence of obesity in childhood and adolescence is continuing rising. Macrophage migration inhibitory factor (MIF) participates in inflammatory and immune responses as a pro-inflammatory cytokine. The present study aimed to investigate MIF in overweight adolescents.

METHODS

Seventy-nine male adolescents were enrolled. Thirty-eight were overweight according to the 90th%ile of the age-specific waist circumference. Various parameters were recorded at one visit, including body mass index. MIF was determined using multiplex immune-assay technology.

RESULTS

Overweight adolescents had increased systolic blood pressure and CRP levels. Furthermore, increased circulating MIF concentrations were observed (Median: 964.6 pg/ml, Interquartile range: 590.3-2019.4 versus Median: 562.7 pg/ml, Interquartile range: 430.6-813.7, p = 0.003). Increased MIF concentrations were associated with increased markers of inflammation and obesity.

CONCLUSIONS

We demonstrated elevated MIF levels in obese adolescents. Taken together with other markers, this indicates the presence of low-grade inflammation in these young subjects, possibly representing a link between obesity and related co-morbidities.

Age-stratified baseline and outcome characteristics of patients undergoing transcatheter aortic valve implantation: results from the German multicenter registry

OBJECTIVES

To analyze age dependencies in patients currently undergoing transcatheter aortic valve implantation (TAVI) based on the German TAVI registry.

BACKGROUND

TAVI is a promising, less invasive treatment option for surgical high-risk patients with symptomatic aortic valve stenosis, with the majority being octogenarians treated so far. Younger patients with significant co-morbidities are now increasingly considered for this procedure, but little is known about this population.

METHODS

The German TAVI registry is an ongoing non-randomized national multicenter study. Consecutive patients who underwent TAVI between January 2009 and June 2010 were included in this analysis. We compared baseline characteristics, procedural characteristics, and short-term clinical outcome up to 30-day follow-up.

RESULTS

A total of 1386 patients were divided into 4 roughly equally-sized groups: group A, n = 347, mean age 73.4 ± 4.5 years; group B, n = 350, mean age 80.6 ± 1.1 years; group C, n = 382, mean age 84.5 ± 1.1 years; and group D, n = 312, mean age 88.9 ± 2.2 years. Patient characteristics varied significantly, with more co-morbidities in younger patients. Technical success rates were similar in all groups (96.6%-97.7%; P=NS). 30-day major adverse event rates were similar with an all-cause mortality rate of 7.2% (A), 7.1% (B), 9.7% (C) and 8.7% (D; P=NS). Postprocedural improvement of both New York Heart Association and self-reported health status was significant in all groups, with significantly better improvements in the categories 'mobility' and 'ability for self-care' in younger patients.

CONCLUSION

TAVI appears to be similarly safe and effective across different age groups with currently applied enrollment criteria, but younger patients present with significantly more co-morbidities. All patient populations experience functional improvements, but this is particularly pronounced for younger patients.

Transcatheter aortic valve implantation in patients with low-flow, low-gradient aortic stenosis

OBJECTIVES

The purpose of this study was to evaluate the efficacy and outcome of transcatheter aortic valve implantation (TAVI) in patients with low-flow, low-gradient aortic stenosis (LG-AS).

BACKGROUND

Patients with LG-AS have a poor prognosis with medical treatment and a high risk for surgical aortic valve replacement.

METHODS

Between January 2009 and June 2010, a total of 1,302 patients underwent TAVI for severe AS and were prospectively included in the multicenter German TAVI registry.

RESULTS

LG-AS was present in 149 patients (11.4%; mean age: 80.2 ± 6.3 years). In this subgroup, the EuroSCORE was significantly higher (26.8 ± 16.6 vs. 20.0 ± 13.3; p < 0.0001) compared with patients with high-gradient AS (HG-AS). The procedural success rate (LG-AS: 95.3% vs. HG-AS: 97.5%; p = 0.13) and the rate of TAVI-associated complications were comparable in both groups (new pacemaker: 27.0% vs. 28.1%; p = 0.76; cerebrovascular events: 3.4% vs. 3.1%, p = 0.83). However, post-operative low-output syndrome occurred more frequently in the LG-AS-group (LG-AS: 14.9% vs. HG-AS: 5.7%, p < 0.0001), and mortality at 30 days and 1 year was significantly higher in this subgroup (LG-AS: 12.8% and 36.9% vs. HG-AS: 7.4% and 18.1%; p < 0.001 and p < 0.0001, respectively). Post-operative New York Heart Association functional class improved, and self-assessed quality of life increased significantly, demonstrating a substantial benefit in the LG-AS group at 30 days and 1 year after TAVI.

CONCLUSIONS

In high-risk patients with LG-AS, TAVI is associated with a significantly higher mortality at 30 days and at 1 year. However, long-term survivors benefit from TAVI with functional improvement and a significantly increased quality of life. Therefore, in view of the poor prognosis with medical treatment, TAVI should be considered an option in high-risk patients with LG-AS.

Testosterone deficiency in male heart failure patients and its effect on endothelial progenitor cells

BACKGROUND

Endothelial progenitor cells (EPCs) are thought to contribute to reendothelialization and neoangiogenesis. Since it is known that EPCs express a testosterone receptor, we wanted to assess the prevalence of testosterone deficiency in patients with CHF and its impact on circulating EPCs.

METHODS

137 male patients with chronic heart failure (CHF) were included (age 61 ± 13 years; BMI 29 ± 5 kg/m(2); New York Heart Association classification (NYHA) I: n = 47, NYHA II: n = 51, NYHA III: n = 39). Numbers of different populations of circulating EPCs were quantified using flow cytometry. Levels of free testosterone and EPC-regulating cytokines were determined using ELISA.

RESULTS

The prevalence of testosterone deficiency in our University CHF clinic was 39%. However, there was no difference between patients with and without testosterone deficiency regarding their levels of EPCs. Testosterone levels were inversely correlated with age (R(2) = -0.32, p = 0.001) and NYHA status (R(2) = 0.28, p = 0.001) and correlated with cardiorespiratory capacity (R(2) = 0.26, p = 0.03).

CONCLUSION

Testosterone deficiency is frequent in male patients with CHF but does not appear to impact the regenerative EPCs.

Immunomodulatory effects of cardiotrophin-1 on in vitro cytokine production of monocytes & CD4 + T-lymphocytes

BACKGROUND & OBJECTIVES

In congestive heart failure (CHF), increased concentrations of several cytokines including cardiotrophin-1 (CT-1) and immunactivation are found. This study was performed to evaluate whether CT-1 can induce in vitro cytokines in monocytes and CD4 + T-lymphocytes of healthy volunteers.

METHODS

The study was performed in vitro to see whether CT-1 can modulate monocyte or CD4 + T-lymphocyte interleukin (IL)-1β, -2, -4, -5, -10, interferon γ (IFNγ), and tumour necrosis factor α (TNFα) expression by flow cytometry following stimulation with CT-1 alone or together with lipopolysaccharide (LPS) or phorbol myristate acetate (PMA)/ionomycine (iono).

RESULTS

CT-1 increased the number of TNFα and IL-1β positive monocytes. LPS induced IL-10, TNFα, and IL-1β in monocytes but only IL-2 in CD4+ T-lymphocytes, whereas PMA/iono induced all cytokines besides IL-5 in monocytes and IL-1β in CD4+ T-lymphocytes. In LPS activated monocytes, CT-1 induced a concentration-dependent reduction in the number of TNFα positive monocytes. After LPS activation, CT-1 decreased the number of CD4+ lymphocytes positive for IL-2, IL-4, and IL-5. In addition, following PMA/iono stimulation, CT-1 initiated a concentration-dependent decrease of CD4 + T-lymphocytes positive for TNFα, IL-4, IL-5, and IL-10.

INTERPRETATION & CONCLUSIONS

The present data show that in vitro CT-1 can activate monocytes and modulate cytokine production of activated CD4 + T-lymphocytes. We speculate that CT-1 may at least be partly responsible for immunactivation in CHF.

Catheter-based renal denervation for drug-resistant hypertension by using a standard electrophysiology catheter

AIMS

The endovascular application of low-dose radiofrequency (RF) energy to the renal arteries results in effective ablation of sympathetic nerve fibres leading to a significant lowering of blood pressure (BP). This study aims to examine the feasibility and safety of renal denervation by the use of a standard electrophysiology (EP) catheter.

METHODS AND RESULTS

Twelve patients (mean age 62±14 years, nine male) with drug resistant hypertension despite medical treatment with at least four antihypertensive drugs underwent renal denervation by using a standard steerable RF ablation catheter with a 7 Fr diameter (Marinr®; Medtronic Inc., Minneapolis, MN, USA). Low-power RF applications have been applied along the length of both renal arteries, consecutively. Assessment of 24 hour ambulatory BP was done at baseline, at one, and at three months following RF ablation. The mean reduction of 24 hour ambulatory BP was -11/-7 mmHg at one month and -24/-14 mmHg at three months (p<0.01 for systolic and p<0.03 for diastolic blood pressure) with unchanged medication. No vascular complications have been observed in the short-term follow-up. The renal function as assessed by serum creatinine and proteinuria remained unchanged from baseline.

CONCLUSIONS

Our preliminary results indicate that the use of a standard RF ablation catheter is feasible and safe for sympathetic renal denervation as shown by a significant lowering of mean 24 hour ambulatory BP in comparison to baseline during short-term follow-up. Whether the use of a standard EP catheter for sympathetic renal denervation indeed improves the long-term outcome in resistant hypertension, however, remains to be investigated.

Positive effect of eplerenone treatment on endothelial progenitor cells in patients with chronic heart failure

Background:

Endothelial progenitor cells (EPCs) are known to play a significant role in reendothelialization and vascular repair. Recently, a mineralocorticoid receptor was demonstrated to be expressed by EPCs. The study aimed to evaluate a potential influence of eplerenone treatment on the total number of EPCs in patients with chronic heart failure.

Methods:

Eighty-seven male patients with chronic heart failure were included (age: 23–83 years; body mass index 29.1 ± 5.1 kg/m2; New York Heart failure classification (NYHA) I: 29 patients, NYHA II: 32 patients, NYHA III: 26 patients). Numbers of circulating EPCs were quantified immediately using flow cytometry. Twenty-eight patients received therapy with eplerenone. Patients were further characterized by echocardiography, spirometry and laboratory markers.

Results:

Patients with ongoing eplerenone administration showed higher levels of circulating cells expressing CD34+ ( p<0.05) and CD34+KDR+ ( p<0.05) and CD34+CD133+KDR+ cells ( p<0.05). The effects of eplerenone treatment could be shown to be independent of NYHA status, genesis of the underlying cardiovascular morbidity, left ventricular function and co-medication.

Conclusion:

Patients with chronic heart failure treated with eplerenone show higher numbers of EPCs. The clinical benefit for treatment with eplerenone has been demonstrated even for patients with mild heart failure and might be partially mediated by EPCs.

Detection of coronary microembolization by Doppler ultrasound in patients with stable angina pectoris during percutaneous coronary interventions under an adjunctive antithrombotic therapy with abciximab: design and rationale of the High Intensity Transient Signals ReoPro (HITS-RP) study

Background

Embolization of atherosclerotic debris from the rupture of a vulnerable atherosclerotic plaque occurs iatrogenically during percutaneous coronary interventions (PCI) and can induce myocardial necrosis. These microembolizations are detected as high intensity transient signals (HITS) using intracoronary Doppler technology.

Presentation of the hypothesis

In the presented study we will test if abciximab (ReoPro®) infusion reduces high intensity transient signals in patients with stable angina pectoris undergoing PCI in comparison to standard therapy alone.

Testing the hypothesis

The High Intensity Transient Signals ReoPro® (HITS-RP) study will enroll 60 patients. It is a prospective, single center, randomized, double-blinded, controlled trial. The study is designed to compare the efficacy of intravenous abciximab administration for reduction of microembolization during elective PCI. Patients will be randomized in a 1:1 fashion to abciximab or placebo infusion. The primary end point of the HITS-RP-Study is the number of HITS during PCI measured by intracoronary Doppler wire. Secondary endpoints are bleeding complications, elevation of cardiac biomarkers or ECG changes after percutaneous coronary interventions, changes in coronary flow velocity reserve, hs-CRP elevation, any major adverse cardio-vascular event during one month follow-up.

Implications of the hypothesis

The HITS-RP-Study addresses important questions regarding the efficacy of intravenous abciximab administration in reducing microembolization and periprocedural complications in stable angina pectoris patients undergoing PCI.

Trial registration

The trial is registered under http://www.drks-neu.uniklinik-freiburg.de/drks_web/:DRKS00000603.

Risk assessment of ventricular arrhythmias in patients with nonischemic dilated cardiomyopathy by strain echocardiography

BACKGROUND

Indications for prophylactic implantable cardioverter-defibrillator implantation in patients with nonischemic dilated cardiomyopathy (DCM) are based on left ventricular (LV) ejection fraction (LVEF), although LVEF has limited ability to predict arrhythmias. It has recently been shown that strain echocardiography can predict ventricular arrhythmias in patients after myocardial infarction. The aim of this study was to evaluate whether strain echocardiography may help in the risk stratification of ventricular arrhythmias in patients with DCM.

METHODS

Ninety-four patients with nonischemic DCM were prospectively included. By speckle-tracking strain echocardiography, global longitudinal strain was calculated as the average of peak longitudinal strain from a 16-segment LV model. The time interval from electrocardiographic peak R to peak negative strain was assessed in each LV segment. Mechanical dispersion was defined as the standard deviation of time to peak negative strain from 16 LV segments.

RESULTS

After a median of 22 months of follow-up (range, 1-46 months), 12 patients (13%) had experienced arrhythmic events, defined as sustained ventricular tachycardia or cardiac arrest. LVEF and global longitudinal strain were reduced in patients with DCM with arrhythmic events compared with those without (28 ± 10% vs 38 ± 13%, P = .01, and -6.4 ± 3.3% vs -12.3 ± 5.2%, P < .001, respectively). Global longitudinal strain showed greater area under the curve than LVEF to identify arrhythmic events in receiver operating characteristic curve analyses (P = .05). Patients with arrhythmic events had increased mechanical dispersion (98 ± 43 vs 56 ± 18 ms, P < .001). Mechanical dispersion predicted arrhythmias independently of LVEF (hazard ratio, 1.28; 95% confidence interval, 1.11-1.49; P = .001).

CONCLUSIONS

Global longitudinal strain is a promising marker of arrhythmias. Mechanical dispersion predicted arrhythmic events in patients with DCM independently of LVEF. Strain echocardiography may help in the risk stratification of patients with DCM not fulfilling current implantable cardioverter-defibrillator indications.

Optimization of the atrioventricular delay during cardiac resynchronization therapy using a device for non-invasive measurement of cardiac index at rest and during exercise

AIMS

It is not clear whether cardiac resynchronization therapy (CRT) should only be optimized at rest or whether it is necessary to perform CRT optimization during exercise. Our study aims to answer this question by using an inert gas rebreathing method (Innocor®).

METHODS AND RESULTS

Twenty-seven patients with congestive heart failure and implanted CRT devices were included in the study. The aetiology of the heart failure was ischaemic in nine (33%) patients. Patients had low left ventricular ejection fraction (29 ± 8%) and enlarged LV end-diastolic diameters (63 ± 7 mm). Atrioventricular delay (AVD) was optimized at rest according to cardiac index (CI), measured by inert gas rebreathing (Innocor®). Thereafter, patients performed standardized, steady-state bicycle exercise at 30 W in sitting body position. Three AVDs were tested during exercise in a random sequence: optimized resting AVD (AVD(opt)) according to baseline measurement; AVD(opt) - 30 ms; and AVD(opt) + 30 ms. Cardiac index was measured in each AVD by inert gas rebreathing. Cardiac index increased significantly during exercise. However, neither AVD(opt) shortening nor prolongation during exercise had significant effect on CI (shortening of AVD(opt) - 30 ms was accompanied by a reduction of CI of 4.8%, prolongation of AVD(opt) + 30 ms was accompanied by a reduction of CI of 7.7%).

CONCLUSION

Shortening or lengthening of the AVD during exercise has no impact on CI in CRT patients. On the basis of our results, we conclude that in CRT patients the AVD should be programmed, fixed even during exercise.

QRS duration and QTc interval are predictors of risk for ventricular arrhythmias during cardiac resynchronization therapy

BACKGROUND AND OBJECTIVES

QRS duration (QRSd) and prolonged corrected QT interval (QTc) are associated with ventricular arrhythmic events. This study was designed to determine whether CRT by means of biventricular pacing alters the QTc and QRSd, and whether such changes are related to the risk of sustained ventricular tachyarrhythmias (sVTA).

METHODS AND RESULTS

A total of 127 patients (102 men, mean age 63.9 +/- 8.9 years) with drug-resistant heart failure and QRS duration > or = 130 ms underwent CRT/CRT-ICD. The aetiology of the heart failure was ischaemic in 41 patients (32.3%). After a median follow-up of 24 months, 42 sVTA occurred in 35 patients (27.6%). Twenty-nine patients had a single sVTA, in five patients two sVTA and in one patient three sVTA occurred. The paced QTc was longer in sVTA patients (505 +/- 55 ms) compared with no sVTA patients (486 +/- 44 ms, P < or = 0.003). Similar responses for paced QRSd were observed (182 +/- 27 ms in sVTA patients vs 167 +/- 27 ms in no-sVTA patients, P < or = 0.03). This effect was independent from intrinsic QTc and QRSd and the aetiology of the heart failure. The mortality rate was significantly higher in patients with ventricular fibrillation and fast VT (P < or = 0.004) who experienced shock therapies. However, the sVTA were not the immediate cause of death.

CONCLUSIONS

A pacing-induced increase in QTc and QRSd is related to sVTA in patients with CRT. Further studies are needed to determine whether optimization of CRT with the goal to achieve a narrow paced QRSd can reduce the occurrence of sVTA.

Microvascular tissue perfusion is impaired in acutely decompensated heart failure and improves following standard treatment

AIMS

Acutely decompensated heart failure (ADHF) leads to neurohumoral activation potentially affecting vascular tone and organ perfusion and may be linked to unfavourable outcome. Global haemodynamic, clinical, and laboratory parameters may severely underestimate tissue hypoperfusion. Therefore, the purpose of this study was to evaluate microvascular flow index (MFI) in patients with ADHF and to assess the effect of standard pharmacological therapy using Sidestream Dark Field (SDF) imaging.

METHODS AND RESULTS

Twenty-seven patients (mean age 75.5 ± 10.1 years, 48% male) with ADHF in New York Heart Association functional class ≥III were included. Serum markers of neurohumoral activation [brain natriuretic peptide (BNP)], endothelin-1 (ET-1), noradrenaline (NA), and echocardiographic parameters of left ventricle-function were determined at hospital admission and the day before discharge. Using SDF imaging, MFI was evaluated at both time-points in semi-quantitative vessel categories (small: 10-25 μm; medium: 26-50 μm; and large: 51-100 μm). At admission, increased serum levels of BNP, NA, and ET-1 and a severely reduced MFI were observed in association with ADHF. Serum levels of BNP, NA, and ET-1 decreased significantly with standard pharmacological therapy (BNP: 2163 ± 1577 vs.1006 ± 945 pg/mL, P< 0.05; NA: 349 ± 280 to 318 ± 265 pg/mL, P< 0.05; ET-1: 5.08 ± 0.72 to 4.81 ± 0.59 pg/mL; P< 0.01). Standard pharmacological treatment also had a profound impact on tissue perfusion by significantly improving median MFI in small [2.6; inter-quartile range (IQR) 2.3-2.9 vs. 2.9; IQR 2.8-3.0; P= 0.01) and medium-sized (2.0; IQR 1.9-2.5 vs. 2.7; IQR 2.5-2.8; P< 0.01) vessels.

CONCLUSION

In patients with ADHF, microvascular tissue perfusion is impaired even when global haemodynamic or laboratory signs of hypoperfusion are absent. Effective pharmacological treatment to decrease neurohumoral activation significantly improves microflow. Hypoperfusion in ADHF is potentially linked to neurohumoral activation with increased plasma levels of vasoconstrictors and sympatho-adrenergic activity.

[Evaluation of microcirculatory disorders in shock patients]

The microcirculatory status depicts an indicator of organ perfusion in hemodynamic shock. Distribution pattern of microcirculatory disturbances reflects the underlying cause of shock: In septic shock, organ perfusion is severely impaired via arteriolo-venous shunting with shutting up small vessel perfusion; however, cardiogenic shock is characterized by a global impairment of microcirculation, involving all vascular beds. Hence, a differentiated evaluation of microcirculatory disturbances not only supports an early diagnosis of an imminent multiorgan dysfunction syndrome (MODS), but also allows a more accurate evaluation of severity of hemodynamic compromise in critical care medicine. Bedside sidestream darkfield (SDF) technique offers the opportunity to describe the microcirculatory status quo semiquantitatively and to evaluate the effect of novel therapeutic approaches on microcirculation. Further technical improvements of this technique may open new fields of diagnostic and therapeutic applications in intensive care medicine by supporting an early diagnosing of MODS, evaluating prognosis, and optimizing therapeutic measures .