Entrapment of circular mapping catheter in the mitral valve

BACKGROUND: Ablation procedures in the left atrium for treatment of atrial fibrillation are becoming increasingly common. The procedure often involves placing one or two circular mapping catheters in the left atrium. Entrapment of an ablation catheter in the mitral valve during ablations of left-sided accessory pathways by the retrograde approach has been described in two earlier published reports. More recently, several reports describe similar entrapment of a mapping catheter. In a recently published review, however, only one case of unspecified valve damage was registered among 8745 atrial fibrillation procedures. OBJECTIVE: The purpose of this study was to evaluate patients with entrapment. METHODS: Retrospective analysis of electrophysiological results. RESULTS: We describe three patients with entrapment during ablations for atrial fibrillation. The entrapments occurred with three different operators at three different electrophysiological laboratories within 2 years. The complication described here may be more common than is widely appreciated. CONCLUSIONS: From our figures, we estimate the incidence of the complication to 0.9% (95% confidence interval, 0.2-2.5%).     

Intensified insulin treatment is associated with improvement in skin microcirculation and ischaemic foot ulcer in patients with type 1 diabetes mellitus: a long-term follow-up study

Aims/hypothesis

We investigated skin microcirculation and its association with HbA_1c and the incidence of ischaemic foot ulcer in patients with type 1 diabetes formerly randomised (1982–1984) to intensified conventional treatment (ICT) or standard treatment (ST) with insulin for a mean of 7.5 years.

Methods

We re-determined the skin microcirculation of 72 patients (ICT 35 vs ST 37) from the original Stockholm Diabetes Intervention Study with iontophoresis topically applied with the following vasoactive stimuli: acetylcholine (ACh) (endothelial-dependent vasodilatation), sodium nitroprusside (SNP) (endothelial-independent vasodilatation), and capsaicin (C-nociceptive-dependent vasodilatation). HbA_1c levels (mean of 14 values/patient) were prospectively collected between 1990 and 1995 and tested for association with skin microcirculation. The patients were followed until first hospitalisation for an ischaemic foot ulcer or until 2011.

Results

During the median 28 years of follow-up, three patients developed ischaemic foot ulcers in the ICT group compared with ten in the ST group (logrank, p?=?0.035). At the time of iontophoresis, HbA_1c was lower in the ICT group (median 57 mmol/mol [minimum–maximum 40–79 mmol/mol]) compared with the ST group (68 mmol/mol [41–96 mmol/mol], p?<?0.01) (DCCT: ICT 7.4% [5.8–9.4%] vs ST 8.4% [5.9–10.9%]). Stimulated blood flow was higher in the ICT vs ST group with significantly increased perfusion units (PU) for: ACh (8.1 PU [4.6–24.7 PU] vs 5.3 PU [1.7–21.4 PU], p?<?0.01); SNP (8.1 PU [2.2–20.1 PU] vs 5.6 PU [2.3–19.2 PU], p?=?0.03); and capsaicin (5.0 PU [1.7–22.9 PU] vs 3.4 PU [1.5–8.4 PU], p?<?0.01). HbA_1c was associated with vasodilatation induced by ACh (b?=??0.02, p?<?0.01) and capsaicin (b?=??0.02, p?=?0.03). HbA_1c was independently associated with ACh (b?=??1.48, p?<?0.01) and capsaicin-induced vasodilatation (b?=??1.45, p?<?0.01).

Conclusions/interpretation

Improved glycaemic control in patients with type 1 diabetes is associated with an improvement in skin microcirculation and with a lower incidence of ischaemic foot ulcers. Trial registration: ClinicalTrials.gov NCT01957930     

Influence of angiotensin converting enzyme inhibition on relation of atrial natriuretic peptide concentration to atrial pressure in heart failure.

OBJECTIVE--To examine the influence of the duration of follow up on the values of heart rate variability (HRV) and the left ventricular ejection fraction (LVEF) for predicting mortality after infarction. BACKGROUND--HRV is an index of autonomic balance that identifies patients at a high risk of arrhythmic events. The index is most depressed during the first few weeks after myocardial infarction whereas left ventricular function tends to deteriorate with time. HYPOTHESIS--The value of depressed HRV measured before discharge from hospital for predicting mortality after infarction should decline with time. METHODS--The HRV and the LVEF were assessed in 433 survivors of a first acute myocardial infarction: HRV < 20 units and LVEF < 40% were taken as cut off points. Kaplan-Meier survival functions for total cardiac mortality and sudden cardiac death were calculated for the whole five year follow up period and for different intervening periods. RESULTS--During follow up of four weeks to five years there were 46 (10.6%) deaths and 15 (3.5%) patients died suddenly. Within the whole follow up period, HRV < 20 units and LVEF < 40% were both strongly associated with total cardiac mortality (p < 0.0001), but HRV was an independent predictor of total cardiac mortality only during the first six months of follow up. There were no deaths predicted by HRV < 20 units after the first year of follow up whereas LVEF < 40% had a sensitivity of 43% and a positive predictive accuracy of 9% for predicting death during this period. HRV < 20 units was better than LVEF < 40% in predicting sudden deaths during the first year of follow up but was an independent predictor only of those sudden deaths occurring within six months of infarction. CONCLUSIONS--The duration of follow up affects the prediction of sudden death and total cardiac mortality from HRV. Reduced HRV as measured before discharge from hospital does not seem to retain independent prognostic value after six months of follow up. These findings have potential implications for the serial evaluation of HRV and for the prevention of sudden death after myocardial infarction.     

Risk factors for coronary heart disease in 55- and 35-year-old men and women in Sweden and Estonia

OBJECTIVE: To illustrate the geographical West-to-East division of coronary heart disease (CHD) by comparing a population from Sweden, that represents a Western country to a population from Estonia, that represents an Eastern country. Estonia has an approximately 2-4-fold higher CHD prevalence for 55-year-old women and men, respectively, than Sweden. DESIGN: Randomized screening of 35- and 55-year-old men and women in Sollentuna county, Sweden and Tartu county, Estonia. Eight hundred subjects, 100 from each cohort, were invited to participate in the study, 272 Swedes and 277 Estonians participated. SETTING: Preventive cardiology, administered by a primary health care centre at the Karolinska Hospital, Sweden and a cardiology centre at Tartu University Hospital, Estonia. MAIN OUTCOME MEASURES: The CHD risk factors (smoking, blood pressure, concentrations of lipoproteins, fibrinogen, and glucose) and certain environmental factors and attitudes related to CHD risk by questionnaires (fat-type and alcohol ingestion, self-assessed rating of CHD susceptibility). RESULTS: Of the 55-year-old men, 57% smoked in Estonia and 20% smoked in Sweden. Similar, although less pronounced differences showing higher smoking prevalence, were seen for 35-year-old Estonian men and women, whilst for 55-year-old women, less than 20% smoked in either country. Estonian 55-year-old women had lower HDL cholesterol and higher LDL cholesterol serum concentrations than Swedish 55-year-old women. Estonians reportedly ate food containing more saturated fats than Swedes, as indicated by the scale-score questionnaire. Estonians, relative to Swedes, rated their chance of developing CHD higher, and paradoxically, Estonians did to a much lesser degree believe that life style influences the risk of developing CHD. CONCLUSIONS: Elevated smoking prevalence is a striking difference between the Estonian and Swedish populations likely to explain the much higher CHD prevalence in Estonian men. The lower HDL cholesterol and higher LDL cholesterol in Estonian 55-year-old women may explain the higher CHD prevalence in Estonian women. Furthermore, the SWESTONIA CHD study (i.e. comparison between Sweden and Estonia) shows several environmental differences between the countries populations related to fat content in food, alcohol drinking patterns, and views on CHD risk and the importance of lifestyle intervention, that could contribute to the higher CHD prevalence in Estonia.     

Cardiac valvular abnormalities are frequent in systemic lupus erythematosus patients with manifest arterial disease

The objective of this study was to study cardiac valve morphology and function and ventricular function in systemic lupus erythematosus (SLE) patients with and without co-existing cardiovascular disease (CVD) and in population controls. Twenty-six women (52 +/- 8.2 years) with SLE (SLE cases) and a history of CVD (angina pectoris, myocardial infarction, cerebral infarction or intermittent claudication) were compared with 26age-matched women with SLE but without manifest CVD (SLE controls) and 26 age-matched control women (population controls). Echocardiographywas performed to assess valvular abnormalities and manifestations of ischaemic heart disease. Thirteen of the 26 SLE cases but only one of the SLE controls and one of the population controls had cardiac valvular abnormalities. Three of the SLE cases had already undergone valve replacement and another had significant aortic insufficiency; the other nine had thickening of mainly mitral leaflets without hemodynamic significance. Among SLE cases, patients with valvular abnormalities had higher homocysteine (P < 0.001) and triglyceride (P = 0.02) concentrations than patients without valvular disease. In contrast atherosclerosis as determined by IMT, oxidized LDL as measured by the monoclonal antibody E06, autoantibodies against epitopes of OxLDL (aOxLDL) or phospholipids (aPL), disease duration or activity, or acute phase reactants did not differ between SLE cases with or without valvular abnormalities. Valvular abnormalities were not more common in SLE cases with stroke as compared to those with myocardial infarction, angina or claudication. In conclusion, valvular abnormalities are strongly associated with CVD in SLE. Raised levels of homocysteine and triglycerides characterize patients with cardiac valve abnormalities.     

Asymptomatic versus symptomatic persistent atrial fibrillation: clinical and noninvasive characteristics

OBJECTIVE: This prospective study was designed to investigate the differences between asymptomatic versus symptomatic arrhythmia as well as left ventricular dysfunction in a consecutive population of patients with persistent atrial fibrillation. DESIGN: A total of 282 consecutive outpatients referred with persistent atrial fibrillation formed the study population. A structured medical history was obtained. A two-dimensional transthoracic echocardiography to assess the left ventricular function and a 24-h electrocardiogram (ECG) recording were performed. Irregularity of the heart rhythm was analysed with heart rate variability (HRV) in the time domain as well as maximum and minimum heart rate and the longest pause. SETTING: Three university hospitals. RESULTS: The mean age of the patients was 69 years and the mean duration of atrial fibrillation was 7 months. The prevalence of symptomatic patients was 68%, while 32% had no symptoms from atrial fibrillation, left ventricular dysfunction was observed in 20%. Asymptomatic subjects had more often lone atrial fibrillation than those with symptoms. Valvular heart disease was an independent predictor of symptoms while male gender, ischaemic heart disease and a high heart rate were independent predictors of impaired left ventricular function. CONCLUSION: Valvular heart disease is related to symptoms in persistent atrial fibrillation. Ischaemic heart disease, male gender and a high heart rate are more common in patients with impaired left ventricular function. Compromised left ventricular function does, occur also in asymptomatic subjects underlining the importance of a careful investigation including echocardiography in all subjects with persistent atrial fibrillation.     

High anaerobic energy release during submaximal arm exercise

Summary. The anaerobic energy release during submaximal arm (AE) and leg exercise (LE) has been estimated from O₂ deficit measured at the onset of exercise. Eight male subjects were studied during 8–10 min of arm or leg cycling at the same relative workload (53% of the peak exercise-induced increase in pulmonary oxygen uptake, VO₂). The workloads were 78 ± 4 W during AE and 173 ± 11 W during LE and Vo₂ was 1.51 ± 006 1 min^-1 for AE and 2.33 ±0.15 1 min^-1 for LE. The half-time of the Vo₂ on-response was considerably longer (P<0.01) during AE (62 ± 9 s) than during LE (33 ± 4 s) and the peak blood lactate concentration was higher (P<0.05) during AE (4.8 ± 0.5 mmol-l^-1) than during LE (3.5 ±0.4 mmol-l^-1). Oxygen deficil was 1.64 ±016 and 1.78 ±0.16 1 for AE and LE respectively. Oxygen deficit was higher during AE than during LE when related to absolute workload (P<0.01), or tc Vo₂ at steady state (P<0.001) or to limb volume (P<0.001). The proportion of the total energy demand covered by anaerobic energy release at the onset of exercise (0–8 min) was about 54% higher (P<0.01) during AE than during LE. It is concluded thai the energy release to a greater extend is covered by anaerobic processes during AE than during LE.     

Transient proarrhythmic state following atrioventricular junction radiofrequency ablation: pathophysiologic mechanisms and recommendations for management

The induction of complete heart block by radiofrequency ablation of the atrioventricular junction combined with pacemaker implantation has become an established therapy for rate control in patients with atrial fibrillation who are unresponsive to drugs. Reports of ventricular arrhythmias and sudden death after ablation have, however, raised concerns about safety. Ventricular arrhythmias are usually polymorphic and related to a phase of electrical instability due to an initial prolongation and then slow adaptation of repolarization caused by the change in heart rate and activation sequence. Structural heart disease, and other factors that predispose for the acquired long QT syndrome, seem to add to the risk. Ventricular activation and repolarization stabilize during the first week after the procedure. Routine pacing at 80 beats per minute during this phase is recommended, as well as in hospital monitoring for at least 48 hours. Patients with high-risk features for arrhythmias, such as congestive heart failure or impaired left ventricular function, may require pacing at higher rates. Adjustment of the pacing rate-although rarely below 70 beats per minute-is usually undertaken after a week in most patients, preferably after an electrocardiographic evaluation for repolarization abnormalities at the lower rate.     

Myocardial perfusion scintigraphy (SPECT) during adenosine stress can be performed safely early on after thrombolytic therapy in acute myocardial infarction

The objective of this study was to evaluate the safety of myocardial perfusion scintigraphy with Tc-99 m sestamibi during adenosine stress in patients with recent thrombolytically treated myocardial infarction. Eighty-four patients with thrombolytically treated myocardial infarction, 59 males and 25 females, aged 62·9 ± 8·4, were eligible for myocardial perfusion scintigraphy during adenosine provocation. Exclusion criteria for adenosine stress were hypotension, unstable angina pectoris, cardiac failure, pericarditis and atrioventricular block (AV block) II–III. Adenosine-stress and resting myocardial perfusion scintigraphy was performed 2–5 days after thrombolysis. Scintigraphy at rest was done 24 h after the stress study. Sixty patients (71%) experienced some kind of side-effects during adenosine infusion. The most frequent side-effects were dyspnoea in 43/84 patients (51%) and unspecific chest discomfort in 26/84 patients (31%). During infusion, ST depressions or elevations on ECG were seen in 9 patients (11%), 5 of whom experienced atypical chest discomfort. Five patients (6%) described typical angina but none of them showed electrographic signs of myocardial ischaemia during infusion. Six patients (7%) developed transient AV block I–II. Reversible scintigraphic perfusion defects were seen in 67 patients (79%). No serious complications, such as death, reinfarction or severe arrhythmias, occurred during adenosine infusion or during a 3-day clinical follow-up period. In conclusion, MIBI-SPECT during adenosine stress is a safe diagnostic method that can be performed in most patients early on after thrombolytically treated acute myocardial infarction. Side-effects are common but benign, and not different from those seen in patients with chronic coronary artery disease.