Standardised pre-hospital care of acute myocardial infarction patients: MISSION! guidelines applied in practice.

Background. To improve acute myocardial infarction (AMI) care in the region 'Hollands-Midden' (the Netherlands), a standardised guideline-based care program was developed (MISSION!). This study aimed to evaluate the outcome of the pre-hospital part of the MISSION! program and to study potential differences in pre-hospital care between four areas of residency.Methods. Time-to-treatment delays, AMI risk profile, cardiac enzymes, hospital stay, in-hospital mortality, and pre-AMI medication was evaluated in consecutive AMI patients (n=863, 61±13years, 75% male) transferred to the Leiden University Medical Center for primary percutaneous coronary intervention (PCI).Results. Median time interval between onset of symptoms and arrival at the catheterisation laboratory was 150 (interquartile range [IQR] 101-280) minutes. The alert of emergency services to arrival at the hospital time was 48 (IQR 40-60) minutes and the door-to-catheterisation laboratory time was 23 (IQR 13-42) minutes. Despite significant regional differences in ambulance transportation times no difference in total time from onset of symptoms to arrival at the catheterisation room was found. Peak troponin T was 3.33 (IQR 1.23-7.04) µg/l, hospital stay was 2 (IQR 2-3) days and in-hospital mortality was 2.3%. Twelve percent had 0 known risk factors, 30% had one risk factor, 45% two to three risk factors and 13% had four or more risk factors. No significant differences were observed for AMI risk profiles and medication pre-AMI. Conclusions. This study shows that a standardised regional AMI treatment protocol achieved optimal and uniformly distributed pre-hospital performance in the region 'Hollands-Midden', resulting in minimal time delays regardless of area of residence. Hospital stay was short and in-hospital mortality low. Of the patients, 88% had ≥1 modifiable risk factor. (Neth Heart J 2010;18:408-15.).

Left ventricular dysfunction due to right ventricular stimulation: is biventricular upgrade really necessary?

Left ventricular (LV) dysfunction can occur due to chronic right ventricular apical pacing. Upgrading of the pacemaker to biventricular pacing is an option to reverse LV dysfunction but reprogramming of the atrioventricular (AV) timing can also be favourable. In this case report we describe the effect of AV-time reprogramming in a patient with LV function deterioration that emerged two years after implantation of a dual chamber system for sick sinus syndrome. Echocardiographc studies demonstrated a tremendous improvement in LV function during two years follow-up whereas the percentage of right ventricular pacing diminished dramatically. Careful analysis of the cause of LV deterioration can avoid unnecessary upgrading to biventricular pacing. (Neth Heart J 2010;18:604-5.).

Recommendations for pacemaker implantation for the treatment of atrial tachyarrhythmias and resynchronisation therapy for heart failure: A report from the task force on pacemaker indications of the Dutch Working Group on Cardiac Pacing.

Today, new pacing algorithms and stimulation methods for the prevention and interruption of atrial tachyarrhythmias can be applied on patients who need bradycardia pacing for conventional reasons. In addition, biventricular pacing as additive treatment for patients with severe congestive heart failure due to ventricular systolic dysfunction and prolonged intraventricular conduction has shown to improve symptoms and reduce hospital admissions. These new pacing technologies and the optimising of the pacing programmes are complex, expensive and time-consuming. Based on many clinical studies the indications for these devices are beginning to emerge. To support the cardiologist's decision-making and to prevent waste of effort and resources, the 'ad hoc committee' has provided preliminary recommendations for implantable devices to treat atrial tachyarrhythmias and to extend the treatment of congestive heart failure respectively.

DDD versus DDDR pacing: effects on the occurrence of atrial arrhythmias and the quality of life in patients with the sick sinus syndrome.

OBJECTIVE: To evaluate the efficiency of adaptive rate dual-chamber pacing to control the recurrence of atrial arrhythmias in patients with the brady-tachy variant of the sick sinus syndrome (SSS) with or without associated AV block. METHOD: A total of 23 patients were included in this double-blind, randomised, crossover study. In each patient a CPI 1230 dual pacemaker was implanted. The pacemaker was programmed blind to the investigator in a randomised order to four different pacing modalities for a period of four weeks each: DDD, lower rate 60 PPM; DDD, lower rate 80 PPM; DDD-R, lower rate 60 PPM; and DDD-R, lower rate 80 PPM. The incidence of atrial tachyarrhythmia events was determined by interrogating the event counter of the pacemaker, 24-hour Holter monitoring in each mode and documentation of the need for reprogramming, electro-cardioversion and antiarrhythmic medication. The quality of life in each pacing mode was assessed by quality-of-life questionnaires and patient diaries. RESULTS: None of the pacing modes were significantly better for the whole patient group with respect to the suppression of atrial arrhythmias. However, there were significant individual differences in the occurrence of atrial tachyarrhythmias and tolerance for each mode. CONCLUSION: In dual-chamber pacing for patients with the brady-tachy variant of the SSS, the ideal programming cannot be predicted. Individual mode setting with usage of the pacemaker event counter should be performed to find the best antitachycardia mode.

Beneficial effect of enalapril on left ventricular remodelling in patients with a severe residual stenosis after acute anterior wall infarction.

OBJECTIVE: The present study was designed to evaluate the effects of early angiotensin converting enzyme (ACE) inhibition on left ventricular enlargement in patients with anterior wall infarction following reperfusion therapy. METHODS: Seventy-one consecutive patients with an anterior wall myocardial infarction were randomly allocated to enalapril (n = 36) or placebo (n = 35). All patients received either thrombolytic therapy (n = 46) or underwent primary coronary angioplasty (n = 25). Medication was started within 48 h admission to hospital and continued for 48 weeks. The process of left ventricular remodelling was assessed with two-dimensional echocardiography at 3 weeks and 1 year after the acute onset, and was related to the severity of the residual stenosis of the infarct-related artery. RESULTS: Baseline left ventricular ejection fraction was 39.2% +/- 8.7%. During the study period left ventricular end-diastolic volume index increased from 48.2 +/- 9.9 ml.m-2 to 54.6 +/- 12.2 ml.m-2 at 3 weeks, and to 59.4 +/- 17.0 ml.m-2 after 1 year I control patients (P < 0.001). In the enalapril-treated patients, left ventricular end-diastolic volume index increased from 50.0 +/- 16.1 to 57.7 +/- 19.3 ml.m-2 at 3 weeks, and to 61.9 +/- 22.7 ml.m-2 after 1 year (P < 0.001). Both at 3 weeks and after 1 year, no overall differences in left ventricular volumes were observed between the enalapril and the placebo group (both ns). However, patients with a residual stenosis severity of > or = 70% in the infarct-related artery (n = 43) showed significant attenuation of remodelling by enalapril (n = 22) when compared to placebo (n = 21). In patients on enalapril, left ventricular end-diastolic volume index increased from 47.0 +/- 13.0 to 53.7 +/- 17.7 ml.m-2 compared to 48.0 +/- 9.6 to 60.3 +/- 16.3 ml.m-2 in control patients (P < 0.03). Also diastolic filling parameters were significantly improved in patients with > or = 70% residual stenosis. CONCLUSION: In patients with an anterior wall infarction and a severe residual infarct-related coronary artery stenosis following reperfusion, treatment with enalapril prevents the process of left ventricular remodelling. As left ventricular dilatation is an early process we suggest that treatment with ACE inhibition should be started as soon as possible in this group of patients.

The short-term effect of intravenous nitroglycerin on haematocrit; an additional benefit in patients with myocardial ischaemia?

Organic nitrates exert their effect by direct inhibition of vascular tone, resulting in decreased myocardial oxygen demand and improved oxygen supply. Less well known is the effect of nitrates on blood rheology. To evaluate the haemodiluting effect of intravenous nitroglycerin we studied 70 consecutive patients admitted to our coronary care unit. The study group consisted of 51 patients with acute chest pain who were treated with nitroglycerin intravenously in a dose between 1 and 5 mg.h-1 during the first 24 h of admission; 19 patients without this treatment were used as controls. In the study group, values of haemoglobin, haematocrit, serum protein and serum albumin, as indirect parameters of haemodilution, all decreased significantly within 24 h, irrespective of the final diagnosis. Similar values were found in the control group. The mean decrease in the haemoglobin value was 0.92 (SD = 0.55) mmol.l-1 vs controls -0.05 (SD = 0.48) mmol.l-1, P < 0.05; the mean decrease in haematocrit was 0.047 (SD = 0.032) vs controls 0.000 (SD = 0.023), P < 0.05. Similar decreases were found in serum protein and albumin values. It is concluded that intravenous nitroglycerin causes a significant decrease in haemoglobin and haematocrit values within 24 h of administration. This altered hemorheologic state may, besides the well known direct vascular effects of nitroglycerin, contribute to the protective effect of nitroglycerin in acute myocardial ischaemia. The effects of nitroglycerin, and the possible mechanisms underlying the decrease in haemoglobin and haematocrit values, will be discussed.

Prolonged dilation with an autoperfusion balloon catheter for refractory acute occlusion related to percutaneous transluminal coronary angioplasty.

OBJECTIVES: Efficacy and safety of redilation by an autoperfusion balloon catheter over several hours were investigated in this retrospective and observational study. BACKGROUND: Acute occlusion, refractory to redilation, is a serious complication of coronary angioplasty. METHODS: Of 1,123 patients who underwent angioplasty, 83 had a refractory acute occlusion. Thiry-five patients were treated with extended dilation. Seven had stable, 19 unstable and 6 postinfarction angina and 3 had an acute infarction at the time of angioplasty. The duration of dilation was (mean +/- SD) 17 (+/- 6) h. RESULTS: Angiographically successful redilation, with a mean residual percent diameter stenosis of 13.5% (+/- 11.6%), was achieved in 22 (67.7%) of 34 patients. Five patients underwent bypass surgery. Three patients, who were poor surgical candidates, died. There was one new Q wave infarction and one death that occurred during extended dilation; one death and four operations were related to reocclusion immediately (< or = 30 min) after catheter withdrawal; and one death and one operation were related to in-hospital reocclusion. Overall success, defined as angiographic success and freedom from major events, was obtained in 20 (57%) of 35 patients (95% confidence interval 41% to 73%). Of the variables studied, only multilesion dilation was significantly (p = 0.018) associated with an unfavorable outcome. During a mean follow-up period of 13.8 (+/- 6.1) months, two patients underwent repeat angioplasty, one sustained an infarction and three underwent elective bypass surgery. CONCLUSIONS: In approximately half of the patients (20 [57%] of 35), an initial angioplasty failure due to refractory occlusion could be reverted to a successful procedure by prolonged dilation with an autoperfusion balloon catheter.

Comparative trial of Omnipaque 350 (iohexol) and Telebrix 350 (sodium-meglumine-ioxithalamate) in left ventriculography and coronary arteriography.

In a double-blind randomized trial, the hemodynamic and electrophysiologic effects of the low-osmolar nonionic contrast medium iohexol (Omnipaque) and the standard high-osmolar ionic monomer sodium-meglumine-ioxithalamate (Telebrix) at left ventricular angiography and selective coronary arteriography were evaluated. Sixty patients were divided into two groups of 30 patients; one group received Omnipaque in a dosage of 350 mgI/ml and the other group received Telebrix in a dosage of 350 mgI/ml. The Omnipaque showed significantly less effects on heart rate and myocardial contractility, and induced less electrophysiological changes than did Telebrix. However, there was a significant increase of 10% in the diameter of the left coronary artery following selective coronary injection with Telebrix, while Omnipaque induced practically no change in vessel diameter. All hemodynamic and electrophysiologic effects proved to be short-lasting. We conclude that ionic and nonionic agents are similarly efficacious in providing adequate images with minimal risk to the patient. However, the nonionic agents exert slightly more alterations in cardiac hemodynamics and in electrocardiographic intervals. The vasodilatory effect on coronary artery diameter by Telebrix may entail a more rapid clearance of contrast medium from the coronary circulation, which might be of some advantage over nonionic contrast media.

Heart conduction disturbance: an HLA-B27 associated disease.

In recent studies from Sweden an increased prevalence of HLA-B27 associated diseases and of HLA-B27 was found in an unselected group of men with permanently implanted pacemakers and with a heart block. Furthermore, a significantly increased prevalence of HLA-B27 was found in men with a pacemaker who had no clinical or radiological signs of HLA-B27 associated disease. To obtain more insight into the association between HLA-B27 and heart block, and the possible role of HLA-B27 in causing this block, a study was made of 35 patients with a pacemaker and heart block of unknown cause, selected from a total group of 350 men with pacemakers who were still alive at the time of the study. One of these 35 men had ankylosing spondylitis and two patients had an asymptomatic sacroiliitis, but all three were HLA-B27 negative. HLA-B27 was present in five (14%) patients, which is a significantly higher prevalence than in healthy controls (17/292, 6%). This percentage is equal to the percentage of HLA-B27 positivity found in the Swedish study on unselected men with an implanted pacemaker, in whom the presence of an HLA-B27 associated disease had been excluded. It suggests that factors other than HLA-B27 are important in the pathogenesis of heart block in most patients.

Short-term and long-term changes of left ventricular volumes during rate-adaptive and single-rate pacing.

To evaluate the adaptation of the heart to exercise during pacing, 15 patients with permanent endocardial pacemakers were studied; nine patients had atrioventricular universal (DDD) pacemakers (Symbios 7005) and six patients had activity detecting rate-responsive ventricular (VVIR) pacemakers (Activitrax 8403). Left ventricular function in each patient during rate variable pacing was compared to ventricular function during VVI single-rate pacing. End-systolic and end-diastolic volume changes during exercise were measured by radionuclide angiography and the amount of volume change was used to assess left ventricular function. Both short-term (within 4 hours) and long-term measurements (after at least 4 weeks) were made at rest and at 50% of the maximal exercise capacity in DDD or VVIR mode and were compared with VVI single-rate pacing. All patients, when changed from DDD or VVIR mode to VVI single-rate pacing showed a significant increase of the end-diastolic volume during exercise, which increased even more after long-term VVI pacing. During long-term rate variable pacing, there was no increase of the end-diastolic volume during exercise. DDD or VVIR pacing initially showed a substantial increase of the end-systolic volume during exercise combined with a decrease of left ventricular ejection fraction, suggesting a decrease of the left ventricular contractility. After 4 weeks, contractility improved both with DDD and VVIR pacing. We conclude that short-term DDD and VVIR pacing induces a temporary impairment of left ventricular function that improves after 4 weeks, whereas long-term VVI pacing is associated with left ventricular dilatation even at moderate levels of exercise.