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Biomedical subjects

P Ritter

Publications and source records attributed to P Ritter.

At least 37 records · Page 2Linked to original sources
PubMed1999

Evidence suggesting that a chronic disease self-management program can improve health status while reducing hospitalization: a randomized trial.

OBJECTIVES: This study evaluated the effectiveness (changes in health behaviors, health status, and health service utilization) of a self-management program for chronic disease designed for use with a heterogeneous group of chronic disease patients. It also explored the differential effectiveness of the intervention for subjects with specific diseases and comorbidities. METHODS: The study was a six-month randomized, controlled trial at community-based sites comparing treatment subjects with wait-list control subjects. Participants were 952 patients 40 years of age or older with a physician-confirmed diagnosis of heart disease, lung disease, stroke, or arthritis. Health behaviors, health status, and health service utilization, as determined by mailed, self-administered questionnaires, were measured. RESULTS: Treatment subjects, when compared with control subjects, demonstrated improvements at 6 months in weekly minutes of exercise, frequency of cognitive symptom management, communication with physicians, self-reported health, health distress, fatigue, disability, and social/role activities limitations. They also had fewer hospitalizations and days in the hospital. No differences were found in pain/physical discomfort, shortness of breath, or psychological well-being. CONCLUSIONS: An intervention designed specifically to meet the needs of a heterogeneous group of chronic disease patients, including those with comorbid conditions, was feasible and beneficial beyond usual care in terms of improved health behaviors and health status. It also resulted in fewer hospitalizations and days of hospitalization.

Adult↗
PubMed1999

Community-based Spanish language arthritis education program: a randomized trial.

OBJECTIVES: To determine 4-month and 1-year health-related outcomes of a 6-week, lay-led, and community-based arthritis self-management program for Spanish-speaking participants and to determine the role of self-efficacy in predicting health status for this population. METHODS: Three hundred and thirty one subjects were randomized to the program or to a 4-month wait list control group. One hundred ninety eight subjects continued in a 1-year longitudinal study. Data were collected via mailed questionnaires with telephone follow up. RESULTS: At 4 months, treatment subjects, compared with controls, demonstrated positive changes in exercise, disability, pain, and self-efficacy (P < 0.05). At 1 year, compared with baseline, treatment subjects demonstrated improvements in exercise, general health, disability, pain, self-efficacy, and depression (P < 0.05). Baseline and 4-month changes in self-efficacy predicted health status at 1 year. CONCLUSIONS: Spanish-speaking participants of an arthritis self-management program demonstrate short- and long-term benefits (improved health behaviors, health status, and self-efficacy).

Adult↗
PubMed1999

[Domestic violence and sexuality].

BACKGROUND: Women's reproductive health is closely related to the conditions in which intercourse is carried out with the sexual partner. Physical and emotional abuse is expressed as loss of bonds, reduction in self esteem and deterioration in interpersonal relationships. AIM: To assess the effects of domestic violence on pregnant women attitudes towards sexual relations with their partners, and to critically analyze the dependence of these variables on biosociodemographic factors, socioeconomic status and family functioning. MATERIAL AND METHODS: Sixty three pregnant women with a domestic violence background (index group) and 43 women without such background (control group) were subjected to a structured survey including questions about biosociodemographic variables, socioeconomic status, family relations, couple interactions and questions about attitudes towards sexual relations. RESULTS: Domestic violence was caused by the woman's partner or ex partner in 73% of cases. A greater family dysfunction and disturbance in the couple's relation was observed in the index group (p < 0.05). Association tests and multiple correspondence analysis did not show a clear correspondence between variables related to a woman's attitude towards sex relations and the risk of domestic violence. CONCLUSIONS: This quantitative methodology was unable to identify the reasons, interpretations and meanings that women with a background of violence, give to features associated with their sexuality.

Adult↗
PubMed1998

Acute hemodynamic effects of biventricular DDD pacing in patients with end-stage heart failure.

OBJECTIVES: The aim of this study was to assess the potential acute benefit of multisite cardiac pacing with optimized atrioventricular synchrony and simultaneous biventricular pacing in patients with drug-refractory congestive heart failure (CHF). BACKGROUND: Prognosis and quality of life in severe CHF are poor. Various nonpharmacological therapies have been evaluated but are restricted in their effectiveness and applications. In the early 1990s, dual chamber pacing (DDD) pacing was proposed as primary treatment of refractory CHF but results were controversial. Recently, tests to evaluate the effect of simultaneous pacing of both ventricles have elicited a significant improvement of cardiac performance. METHODS: Acute hemodynamic study was conducted in 18 patients with severe CHF (New York Heart Association class III and IV) and major intraventricular conduction block (IVCB) (QRS duration = 170+/-37 ms). Using a Swan-Ganz catheter, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP) and cardiac index (CI) were measured in different pacing configurations: atrial pacing (AAI) mode, used as reference, single-site right ventricular DDD pacing and biventricular pacing with the right ventricular lead placed either at the apex or at the outflow tract. RESULTS: The CI was significantly increased by biventricular pacing in comparison with AAI or right ventricular (RV). DDD pacing (2.7+/-0.7 vs. 2+/-0.5 and 2.4+/-0.6 l/min/m2, p < 0.001). The PCWP also decreased significantly during biventricular pacing, compared with AAI (22+/-8 vs. 27+/-9 mm Hg; p < 0.001). CONCLUSIONS: This acute hemodynamic study demonstrated that biventricular DDD pacing may significantly improve cardiac performance in patients with IVCB and with severe heart failure, in comparison with intrinsic conduction and single-site RV DDD pacing.

Aged↗
PubMed1998

Reliability of an automatic sensing test with beat-to-beat display of the signal amplitude.

In contrast to testing of the capture threshold, the reliability of sensing tests has been little studied. This study was performed to test the automatic sensing algorithm included in the Biotronik pacing systems. The automatic measurements made by the devices were compared with the direct manual measurements made of 271 atrial (72%) or ventricular (28%) electrograms recorded in ten patients. A high correlation (r = 0.995, P < 0.0001) was found between the two types of measurements. The use of this function should facilitate the verification of accurate sensing during the long-term follow-up of pacemaker patients, and offers a tool to analyze the variations in amplitude of intracardiac signals.

Algorithms↗
PubMed1998

Measurement of minute ventilation with different DDDR pacemaker electrode configurations. Investigators of a Multicenter Study Evaluating the Chorus RM and Opus RM Pacemakers.

A rate responsive minute ventilation (VE) pacemaker was implanted in 49 patients (70.8 +/- 40.0 years). A Chorus RM 7034 pacemaker was implanted in 43 patients and an Opus RM 4534 in six patients. Four sensor configurations were compared: atrial configuration (bipolar atrial lead) in 34 patients; ventricular configuration (bipolar ventricular lead) in 6 patients; unipolar configuration (double unipolar leads) in 6 patients; and floating configuration (VDD single-pass lead) in 3 patients. The patients carried out 57 exercise tests in all with cardiopulmonary recording (CPX). Real VE and oxygen consumption (VO2) were recorded by the CPX, the VE measured by the sensor (VEsensor) was recorded in the pacemaker memory. The mean correlation between VE and VEsensor was 0.90 +/- 0.08 (P < 0.001) and between VO2 and VEsensor was 0.86 +/- 0.10 (P < 0.001). The mean correlation between VE and VEsensor by configuration type were as follows: atrial configuration = 0.89 +/- 0.08; ventricular configuration = 0.95 +/- 0.05; unipolar configuration = 0.87 +/- 0.14; and floating configuration = 0.88 +/- 0.05. In conclusion, VE may be reliably measured using different electrode configurations. A study conducted in a larger population should allow one to conclude that unipolar electrodes can be used in VDDR, AAIR, VVIR, or DDDR modes to measure VE.

Aged↗
PubMed1998

Permanent left ventricular pacing with transvenous leads inserted into the coronary veins.

This paper describes a preliminary experiment-conducted jointly by 2 centers-of permanent left ventricular pacing using leads inserted by the transvenous route and through the coronary sinus into the cardiac veins of the left ventricle free wall. The aim was to obtain permanent biventricular pacing in a totally endocavitary configuration in patients with severe LV dysfunction and drug-refractory heart failure. Two types of leads were used: nonspecific unipolar leads at the beginning of the experiment, followed by leads specifically designed to be used in the coronary sinus in a second step. The electrode could be fitted in an adequate location in 35 of the 47 patients (75.4%), with a 1.15 +/- 0.7 V acute pacing threshold and 11.8 +/- 5.7 mV R wave amplitude. The success rate was significantly higher with the specific electrodes (81.8% vs 53.3%, p < 0.001). The pacing and sensing thresholds upon implantation were not influenced by the type of lead or by the localization of the cardiac vein that was catheterized (great cardiac vein, lateral vein, postero-lateral or posterior vein, mid cardiac vein). In contrast, the pacing threshold was significantly lower (0.8 +/- 0.2 vs 1.8 +/- 0.8 V; p = 0.002) and the R wave amplitude tended to be greater (13.1 +/- 4.5 mV vs 9.3 +/- 6.5 mV; p = 0.07) when the tip electrode could be inserted distally into the vein, by comparison with a proximal site near the ostium. At the end of follow-up (10.2 +/- 8.7 months), 34 out of the 35 leads were still fully functional, with a chronic pacing threshold of 1.8 +/- 0.7 V and a R wave amplitude of 10.7 +/- 6 mV. To conclude, permanent LV pacing via the transvenous route is possible in most patients, with excellent safety and long-term results.

Aged↗
PubMed1998

Reduction in energy pacing thresholds by overlapping biphasic stimulation versus conventional bipolar pacing.

UNLABELLED: Overlapping biphasic (OLBI) stimulation is a new pacing waveform consisting of two simultaneous monophasic pulses of opposite polarities applied to a bipolar electrode. The goal of this prospective study was to compare, using conventional pacing leads, the acute energy pacing thresholds, measured at 0.5-ms pulse duration, associated with bipolar versus OLBI (mode 7 and mode 8) pulse delivery. RESULTS: Thirty one leads were tested in 20 patients. Of these leads, 7 (23%) were implanted chronically, 12 (39%) were in atrial positions, and 19 (61%) in ventricular positions. Energy pacing thresholds were significantly lower (-25.6 +/- 25.6%, P = 0.005) in OLBI mode 8 (1.30 +/- 3.96 microJ) compared to bipolar (1.55 +/- 4.37 microJ) pacing, regardless of the pacing site or length of service of the leads. In contrast, OLBI mode 7, which has an anodal component, at the tip electrode was associated with higher energy pacing thresholds (3.65 +/- 6.48 microJ; +358.3 +/- 219.4%, P = 0.002). CONCLUSIONS: Mode 8 OLBI pacing is associated with lower acute energy pacing thresholds when used with bipolar leads in contact with the myocardium. OLBI pacing may increase pacemaker longevity by reducing long-term energy consumption.

Arrhythmias, Cardiac↗
PubMed1998

[Pacing and heart failure].

Conventional dual-chamber cardiac pacing with the right ventricular pacing catheter positioned at the apex of the right ventricle was proposed eight years ago by Hochleitner as primary treatment of refractory cardiac failure. Although the preliminary results were encouraging, those at long-term and subsequent studies were less favourable in this indication. Biventricular pacing is now a technical possibility and allows at least partial correction of the electromechanical abnormalities observed in dilated cardiomyopathy. The preliminary results of biventricular pacing in patients with refractory cardiac failure due to dilated cardiomyopathy with major intraventricular conduction defects are very encouraging. This new therapeutic approach should now be validated by controlled, randomised therapeutic trials.

Cardiac Catheterization↗
PubMed1997

Preliminary clinical experience with the first dual chamber pacemaker defibrillator.

The lack of specificity of VT detection is a significant shortcoming of current ICDs. In a French multicenter study, 18 patients underwent implantation of the Defender 9001 (ELA Medical), an ICD utilizing dual chamber pacing and arrhythmia detection. Over a mean follow-up period of 7.1 +/- 4.5 months, 176 tachycardia episodes recorded in the device memory were analyzed, and physician diagnosis was compared with that by the device. All 122 VT/VF episodes were correctly diagnosed, as were 51 of 53 supraventricular tachyarrhythmias. Two episodes of AF with rapid regular ventricular rates were treated as VT, and a third episode, treated as VT, could not be diagnosed with certainty. A dual chamber pacemaker defibrillator offers improved diagnostic specificity without loss of sensitivity, in addition to the hemodynamic benefit of dual chamber pacing.

Adolescent↗
PubMed1996

Multisite pacing for end-stage heart failure: early experience.

Our objective was to improve hemodynamics by synchronous right and left site ventricular pacing in patients with severe congestive heart failure (CHF). Previous studies reported a benefit of dual chamber pacing with a short AV delay in patients with severe CHF. Other works, however, show contradictory results. Deleterious effects due to a desynchronization of right (RV) and left ventricular (LV) contractions have been suggested. This study included eight subjects with widened QRS and end-stage heart failure despite maximal medical therapy, who refused, or were not eligible to undergo heart transplantation, Each patient underwent a baseline, invasive hemodynamic evaluation with insertion of three temporary leads to allow different pacing configurations, including RV apex and outflow tract pacing, and biventricular pacing between the RV outflow tract and LV and RV apex and LV. According to the results of this baseline study, the configuration of preexistent pacemakers was modified or new systems were implanted to allow biventricular pacing, which, in patients with sinus rhythm, was atrial triggered. Biventricular pacing increased the mean cardiac index (CI) by 25% (from a baseline of 1.83 +/- 0.30 L/min per m2, P < 0.006), decreased the mean V wave by 26% (from a baseline of 36 +/- 12 mmHg, P < 0.004), and decreased pulmonary capillary wedge pressure by 17% (from a baseline of 31 +/- 10 mmHg, P < 0.01). Four patients died (1 preoperatively, 1 intraoperatively, 2 within 3 months, and 1 of a noncardiac cause). The four surviving patients have clinically improved from New York Heart Association Functional Class IV to Class II. In these survivors, CI decreased by 15% (P < 0.007) when multisite pacing was turned off during follow-up. In patients with end-stage heart failure, multisite pacing may be associated with a rapid and sustained hemodynamic improvement.

Aged↗
PubMed1996

A randomized, single-blind crossover comparison of the effects of chronic DDD and dual sensor VVIR pacing mode on quality-of-life and cardiopulmonary performance in complete heart block.

The aim of this study was to compare DDD and dual sensor VVIR (activity and QT) pacing modes in complete AV block (CAVB). Eighteen patients (14 men and 4 women, aged 70 +/- 6.5 years) implanted with a dual chamber, dual sensor pacemaker for CAVB with normal sinus node chronotropic function were studied. A quality-of-life and cardiovascular symptom questionnaire, and a treadmill exercise test were completed after a period of VVIR and a period of DDD pacing, each lasting 1 month. Overall quality-of-life and cardiovascular symptoms did not significantly differ, though three patients felt discomfort during VVIR mode. There was no significant statistical difference in cardiopulmonary parameters. DDD and VVIR modes yielded the following respective data: maximum heart rate = 105.7 +/- 21.8 beats/minute versus 107.6 +/- 21.6 beats/minute (NS); maximum workload = 60 +/- 33.4 W versus 59.3 +/- 37.8 W (NS); treadmill duration = 10.1 +/- 3.8 minute versus 10.1 +/- 3.6 minute (NS); oxygen consumption at anaerobic threshold = 14.6 +/- 4.1 mL/kg per minute versus 14.9 +/- 4.6 mL/kg per minute (NS); maximum minute ventilation = 49.6 +/- 9L/min versus 46 +/- 12 L/min (NS); and respiratory quotient = 1.08 +/- 0.15 versus 1.08 +/- 0.13 (NS). We conclude that, during a 1-month follow-up period, no difference was found between DDD and dual sensor VVIR (QT and activity) pacing modes in CAVB patients with regard to quality-of-life and cardiopulmonary performance, though a trend toward an increased sense of well being was noted with the DDD mode.

Aged↗
PubMed1996

Short term effects of air pollution on mortality in the city of Lyon, France, 1985-90.

OBJECTIVE: The short term association between daily mortality and ambient air pollution in the city of Lyon, France (population, 410,000) between 1985 and 1990 was assessed using time series analysis. DESIGN: This study followed the standardised design and statistical analysis (Poisson regression) that characterise the APHEA project. METHODS: Four categories of cause of death were studied: total (minus external causes), respiratory, cardiovascular, and digestive causes (as a control condition). RESULTS: No association was found with any cause of death for nitrogen dioxide (NO2) and ozone (O3), nor, for any pollutant, for digestive conditions. Sulphur dioxide (SO2) and, to a much lesser degree, suspended particles (PM13), were significantly related to mortality from respiratory and cardiovascular conditions. The relative risk (RR) of respiratory deaths associated with a 50 micrograms/m3 increment of mean daily SO2 over the whole period was 1.22 (95% CI 1.05, 1.40); the RR for cardiovascular deaths was 1.54 (1.22, 1.96). The corresponding RRs for PM13 were 1.04 (1.00, 1.09) for respiratory mortality and 1.04 (0.99, 1.10) for cardiovascular deaths. CONCLUSIONS: The effects of particulates were slightly increased during the cold season. When particulates concentrations were greater than 60 micrograms/m3, the joint SO2 effect was increased, suggesting some interaction between the two pollution indicators. These results agree with other studies showing an association between particulate pollution and daily mortality; however, they also suggest the noxious effect of SO2.

Air Pollutants↗
PubMed1996

[Incidence of atrial arrhythmia in patients with long term dual-chamber pacemakers. Contribution of the Holter function of pacemakers].

The extension of the RAM memories in the latest generation of pacemakers has enabled development of Holter function allowing continuous surveillance of the cardiac rhythm. Between October 1991 and February 1995, 213 patients implanted with a Chorus 6234 or 7034 (Ela Medical) pacemaker, functioning in the DDD (R) mode, were followed up using the implanted continuous Holter function. Of the patients with no documented supraventricular arrhythmia (SVA) before implantation (n = 154), 67 (43.5%) developed SVA during an average period of one year. Male patients (p = 0.01; OR = 7.5 on multivariate analysis), high degrees of AVB (p = 0.03) and the presence of isolated or bursts of atrial extrasystoles (p = 0.004) were independent risk factors for SVA. The average time to detection of SVA was 207 days. In patients with documented SVA before implantation (n = 59), 22 (37.3%) had no recurrence during follow-up; in the other 37 cases, the average period before recurrence was 127 days. Multivariate analysis did not reveal any independent risk factor for recurrence of the arrhythmias. On the other hand, persistent but delayed atrioventricular conduction (1 degree AVB, long H-V interval or bifascicular block), seemed to protect against SVA, independently of other variables and of antiarrhythmic therapy (p = 0.008). These results suggest a high prevalence of SVA in patients on long-term pacemaker therapy, most episodes being asymptomatic. The implanted Holter function would therefore seem to be an essential tool for investigating and following up the natural history of arrhythmias in these patients.

Aged↗
PubMed1996

[First experience in treatment of terminal cardiac insufficiency using multisite stimulation].

We hypothesized that the presence of an abnormal ventricular mechanical activation sequence and/or a delayed left ventricular (LV) contraction may have adverse hemodynamic effects in congestive heart failure (CHF) and could be improved by synchronous RV-LV pacing in a multisite (MS) configuration. 8 NYHA IV CHF patients were included with a LV delay due to 1/ preexistent pacemaker in 4 pts (2 VVI and 2 DDD); 2/ left bundle branch block in 2 pts; 3/ intraventricular conduction delays in 2 pts. An acute hemodynamic evaluation was performed. Hemodynamics were optimized in standard RV pacing by modifying RV lead position from apex to outflow tract (RVOT) in VVI for AF patients and in VDD for sinus rhythm patients at different AV delays. RV pacing did not change hemodynamics whatever the lead position. BV pacing improved CI by 25% (p < 0.006), V wave by 26% (p < 0.004) and PCWP by 17% (p < 0.01). Chronic implantation was performed in 7pts. LV lead was implanted via the coronary sinus in 2 cases and epicardial via a thoracoscopic approach in the remaining ones. 1 pt died during LV lead implantation. Hemodynamics were tested at 2 months followup (FU). Switching BV pacing off was associated with immediate deterioration. At 6 +/- 6 months Followup 4 pts are stable in Class II. 1 pt died of cardiac cause. 1 pt could be transplanted at 17 months FU. In conclusion, BV pacing through a multisite configuration is feasible and can help in CHF patients managing.

Aged↗
PubMed1995

Carotid sinus syndrome: acute hemodynamic evaluation of a dual chamber pacing mode.

Cardiac pacing is the treatment of choice in patients with carotid sinus syndrome (CSS). Three different pacing modes were tested in 20 patients (16 males, 4 females; mean age 75 +/- 9 years) with documented symptomatic CSS. Three carotid sinus massages (CSM) were performed in each supine patient successively paced in random order in: DDI--the reference pacing mode; DDD--automatic mode conversion (DDD/AMC) allowing automatic switching from AAI to DDD when AV block occurs; DDD/AMC plus atrial acceleration (DDD/AMC+acc); and OOO (CSM without pacing) to determine whether the vasodepressive effect was still present 10 minutes after the preceding CSM. Intraarterial blood pressure was continuously monitored. Results were expressed as the value of the mean systolic BP at T0 + 3 s + 6 s ... T0 + 30 s divided by the value of the mean systolic blood pressure prior to onset of CSM. The drop in arterial blood pressure was more severe in the DDI mode than in DDD/AMC (P < 0.001) and DDD/AMC+acc (P < 0.0001) in 20 patients. In the OOO mode, the drop in arterial blood pressure was most marked and greater than in the DDI mode (P < 0.0001). The average time between start of the CSM and onset of the drop in blood pressure was the same in the three dual chamber modes. We conclude that the DDD/AMC mode significantly improves the vasodepressor response to CSM compared to the DDI mode. There is a current trend favoring DDD/AMC+acc over DDD/AMC.

Aged↗
PubMed1994

Prevalence of chronic pain after pulmonary resection by thoracotomy or video-assisted thoracic surgery.

The prevalence and severity of chronic pain after video-assisted thoracic surgery for pulmonary resection remains to be defined. Three hundred forty-three of 391 consecutive patients 3 to 31 months after pulmonary resection by lateral thoracotomy (n = 165) or video-assisted thoracic surgery (n = 178) responded to a questionnaire aimed at comparing the relative occurrence of chronic postoperative pain after video-assisted thoracic surgery and lateral thoracotomy approaches for pulmonary resection. Patients less than 1 year after operation (video-assisted thoracic surgery = 142; thoracotomy = 97) and more than 1 year after operation (video-assisted thoracic surgery = 36; thoracotomy = 68) were analyzed as individual cohorts. Chronic pain was assessed by questioning patients about the presence and the intensity of discomfort on the side of the operation (using a visual analog scale) and their need for analgesic medication and the presence of ongoing limitations in shoulder function. Patients who underwent video-assisted thoracic surgery (less than 1 year from operation) had less pain and subjective shoulder dysfunction although their pain medication requirements were similar to those of thoracotomy patients less than 1 year from operation. After 1 year, there was no significant difference in these "pain related" morbidity parameters between the two surgical approach groups (video-assisted thoracic surgery or thoracotomy).

Chronic Disease↗