Part 5: Acute coronary syndromes

Oxygen therapy in patients with ST elevation myocardial infarction based on the culprit vessel: results from the randomized controlled SOCCER trial

BACKGROUND

Oxygen (O₂) treatment has been a cornerstone in the treatment of patients with myocardial infarction. Recent studies, however, state that supplemental O₂ therapy may have no effect or harmful effects in these patients. The aim of this study was thus to evaluate the effect of O₂ therapy in patients with ST Elevation Myocardial Infarction (STEMI) based on the culprit vessel; Left Anterior Descending Artery (LAD) or Non-LAD.

METHODS

This was a two-center, investigator-initiated, single-blind, parallel-group, randomized controlled trial at the Skåne university hospital, Sweden. A simple computer-generated randomization was used. Patients were either randomized to standard care with O₂ therapy (10 l/min) or air until the end of the primary percutaneous coronary intervention. The patients underwent a Cardiac Magnetic Resonance Imaging (CMRI) days 2-6. The main outcome measures were Myocardium at Risk (MaR), Infarct Size (IS) and Myocardial Salvage Index (MSI) as measured by CMRI, and median high-sensitive troponin T (hs-cTnT).

RESULTS

A total of 229 patients were assessed for eligibility, and 160 of them were randomized to the oxygen or air arm. Because of primarily technical problems with the CMRI, 95 patients were included in the final analyses; 46 in the oxygen arm and 49 in the air arm. There were no significant differences between patients with LAD and Non-LAD as culprit vessel with regard to their allocation (oxygen or air) with regards to MSI, MaR, IS and hs-cTnT.

CONCLUSION

The results indicate that the location of the culprit vessel has probably no effect on the role of supplemental oxygen therapy in STEMI patients.

TRIAL REGISTRATION

Swedish Medical Products Agency (EudraCT No. 2011-001452-11) and ClinicalTrials.gov Identifier (NCT01423929).

Effect of oxygen therapy on chest pain in patients with ST elevation myocardial infarction: results from the randomized SOCCER trial

OBJECTIVE

Oxygen (O₂) have been a cornerstone in the treatment of acute myocardial infarction. Studies have been inconclusive regarding the cardiovascular and analgesic effects of oxygen in these patients. In the SOCCER trial, we compared the effects of oxygen treatment versus room air in patients with ST-elevation myocardial infarction (STEMI). There was no difference in myocardial salvage index or infarct size assessed with cardiac magnetic resonance imaging. In the present subanalysis, we wanted to evaluate the effect of O₂ on chest pain in patients with STEMI.

DESIGN

Normoxic patients with first time STEMI were randomized in the ambulance to standard care with 10 l/min O₂ or room air until the end of the percutaneous coronary intervention (PCI). The ambulance personnel noted the patients´ chest pain on a visual analog scale (VAS; 1-10) before randomization and after the transport but before the start of the PCI, and also registered the amount of morphine given.

RESULTS

160 patients were randomized to O₂ (n = 85) or room air (n = 75). The O₂ group had a higher median VAS at randomization than the air group (7.0 ± 2.3 vs 6.0 ± 2.9; p = .02) and also received a higher median total dose of morphine (5.0 mg ± 4.4 vs 4.0 mg ± 3.7; p = .02). There was no difference between the O₂ and air groups in VAS at the start of the PCI (4.0 ± 2.4 vs 3.0 ± 2.5; p = .05) or in the median VAS decrease from randomization to the start of the PCI (-2.0 ± 2.2 vs -1.0 ± 2.9; p = .18).

CONCLUSION

Taken together with previously published data, these results do not support a significant analgesic effect of oxygen in patients with STEMI. European Clinical Trials Database (EudraCT): 2011-001452-11. ClinicalTrials.gov Identifier: NCT01423929.

Oxygen therapy for acute myocardial infarction

BACKGROUND

Oxygen (O₂) is widely used in people with acute myocardial infarction (AMI). Previous systematic reviews concluded that there was insufficient evidence to know whether oxygen reduced, increased or had no effect on heart ischaemia or infarct size. Our first Cochrane review in 2010 also concluded there was insufficient evidence to know whether oxygen should be used. Since 2010, the lack of evidence to support this widely used intervention has attracted considerable attention, prompting further trials of oxygen therapy in myocardial infarction patients. It is thus important to update this Cochrane review.

OBJECTIVES

To assess the effects of routine use of inhaled oxygen for acute myocardial infarction (AMI).

SEARCH METHODS

We searched the following bibliographic databases on 6 June 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (OVID), Embase (OVID), CINAHL (EBSCO) and Web of Science (Thomson Reuters). LILACS (Latin American and Caribbean Health Sciences Literature) was last searched in September 2016. We also contacted experts to identify eligible studies. We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials in people with suspected or proven AMI (ST-segment elevation myocardial infarction (STEMI) or non-STEMI) within 24 hours after onset, in which the intervention was inhaled oxygen (at normal pressure) compared to air, regardless of co-therapies provided to participants in both arms of the trial.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the titles and abstracts of identified studies to see if they met the inclusion criteria and independently undertook the data extraction. We assessed the quality of studies and the risk of bias according to guidance in the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was death. The measure of effect used was the risk ratio (RR) with a 95% confidence interval (CI). We used the GRADE approach to evaluate the quality of the evidence and the GRADE profiler (GRADEpro) to import data from Review Manager 5 and create 'Summary of findings' tables.

MAIN RESULTS

The updated search yielded one new trial, for a total of five included studies involving 1173 participants, 32 of whom died. The pooled risk ratio (RR) of all-cause mortality in the intention-to-treat analysis was 0.99 (95% CI 0.50 to 1.95; 4 studies, N = 1123; I² = 46%; quality of evidence: very low) and 1.02 (95% CI 0.52 to 1.98; 4 studies, N = 871; I² = 49%; quality of evidence: very low) when only analysing participants with confirmed AMI. One trial measured pain directly, and two others measured it by opiate usage. The trial showed no effect, with a pooled RR of 0.97 for the use of opiates (95% CI 0.78 to 1.20; 2 studies, N = 250). The result on mortality and pain are inconclusive. There is no clear effect for oxygen on infarct size (the evidence is inconsistent and low quality).

AUTHORS' CONCLUSIONS

There is no evidence from randomised controlled trials to support the routine use of inhaled oxygen in people with AMI, and we cannot rule out a harmful effect. Given the uncertainty surrounding the effect of oxygen therapy on all-cause mortality and on other outcomes critical for clinical decision, well-conducted, high quality randomised controlled trials are urgently required to inform guidelines in order to give definitive recommendations about the routine use of oxygen in AMI.

Prehospital transportation to therapeutic hypothermia centers and survival from out-of-hospital cardiac arrest

Background

Clinical trials supporting the use of therapeutic hypothermia (TH) in the treatment of out-of-hospital cardiac arrest (OHCA) are based on small patient samples and do not reflect the wide variation in patient selection, cooling methods, and other elements of post-arrest care that are used in everyday practice. This study provides a real world evaluation of the effectiveness of post-arrest care in TH centers during a time of growing TH dissemination in the state of New Jersey (NJ).

Methods

Using a linked database of prehospital, hospital, and mortality records for NJ in 2009-2010, we compared rates of neurologically intact survival at discharge and at 30 days for OHCA patients transported to TH centers (N = 2363) versus other hospitals (N = 2479). We used logistic regression to adjust for patient and hospital covariates. To account for potential endogeneity in prehospital transportation decisions, we used an instrumental variable (IV) based on differential distance to the nearest TH and non-TH hospitals.

Results

Patients taken to TH centers were older, more likely to have a witnessed arrest, more likely to receive defibrillation, and waited a shorter amount of time for initial EMS response. Also, TH hospitals were larger, more likely to be teaching facilities, and operated in a service area with a relatively lower poverty rate compared to hospitals statewide. A Stock-Yogo test confirmed the strength of our IV (F = 2349.91, p < 0.0001). Nevertheless, the data showed no evidence of endogenous transportation to TH centers related to in-hospital survival (Z = -0.08, p = 0.934) or 30-day survival (Z = 0.94, p = 0.349). In logistic regression models, treatment at a TH center was associated with greater odds of 30-day neurologically intact survival (OR = 1.70; 95 % CI: 1.19 – 2.42) but not associated with the odds of neurologically intact survival to hospital discharge (OR = 0.90; 95 % CI: 0.61 – 1.31).

Conclusions

Post-arrest outcomes are more favorable at TH centers but these improved outcomes are not apparent until after hospital discharge. This finding may reflect superior care by TH centers in later stages of post-arrest treatment such as care provided in the intensive care unit, which has greater potential to affect longer term outcomes than initial treatment in the emergency department.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-1199-z) contains supplementary material, which is available to authorized users.

Post-cardiac arrest therapeutic hypothermia in New Jersey hospitals: analysis of adoption and implementation

BACKGROUND

While national guidelines recommend the use of therapeutic hypothermia (TH) for the treatment of out-of-hospital cardiac arrest (OHCA), adoption of the technique has been slow. In addition, little is known about how TH is applied in practice. This study sought to characterize the adoption and implementation of TH by acute care hospitals in the state of New Jersey.

METHODS

A survey of all 73 acute care hospitals in New Jersey was conducted to solicit information about TH adoption, application, and methods. Additional information was gained through a review of 18 written TH protocols (covering 21 hospitals).

RESULTS

After growing slowly from 2004 to 2008, TH use among New Jersey hospitals accelerated between 2009 and 2011. By 2011, 68.4% of New Jersey hospitals had a TH program in place, with an additional 13.6% indicating plans to begin one. Most hospitals indicated low volumes of OHCA patients (e.g., ≤10 per month). There was no relationship between OHCA volume and development of a TH program. The per hospital volume of OHCA patients receiving TH is even lower given the extensive patient exclusion criteria used by many facilities. TH hospitals vary widely in their TH exclusion criteria and cooling equipment and methods.

DISCUSSION

The vast majority of New Jersey hospitals are now organized to implement national TH guidelines for initial survivors of OHCA. However, limited volumes of OHCA cases per hospital and lack of uniformity on how the guidelines are implemented raise new questions about the effectiveness of current practice in postarrest care. More detailed analysis of TH volumes versus outcomes and comparative studies of TH techniques are required to optimize postarrest care.

Oxygen therapy for acute myocardial infarction

BACKGROUND

Oxygen (O₂) is widely used in people with acute myocardial infarction (AMI) although it has been suggested it may do more harm than good. Previous systematic reviews have concluded that there was insufficient evidence to know whether oxygen reduced, increased or had no effect on heart ischaemia or infarct size, as did our original Cochrane review on this topic in 2010. The wide dissemination of the lack of evidence to support this widely-used intervention since 2010 may stimulate the needed trials of oxygen therapy, and it is therefore important that this review is updated regularly.

OBJECTIVES

To review the evidence from randomised controlled trials to establish whether routine use of inhaled oxygen in acute myocardial infarction (AMI) improves patient-centred outcomes, in particular pain and death.

SEARCH METHODS

The following bibliographic databases were searched last in July 2012: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (OVID), EMBASE (OVID), CINAHL (EBSCO) and Web of Science (ISI). LILACS (Latin American and Caribbean Health Sciences Literature) and PASCAL were last searched in May 2013. We also contacted experts to identify any studies. We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials of people with suspected or proven AMI (ST-segment elevation myocardial infarction (STEMI) or non-STEMI), less than 24 hours after onset, in which the intervention was inhaled oxygen (at normal pressure) compared to air and regardless of cotherapies provided these were the same in both arms of the trial.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the titles and abstracts of identified studies to see if they met the inclusion criteria, and independently undertook the data extraction. The quality of studies and the risk of bias were assessed according to guidance in the Cochrane Handbook. The primary outcomes were death, pain and complications. The measure of effect used was the risk ratio (RR) with a 95% confidence interval (CI).

MAIN RESULTS

The updated search identified one new trial. In total, four trials involving 430 participants were included and 17 deaths occurred. The pooled RR of death was 2.05 (95% CI 0.75 to 5.58) in an intention-to-treat analysis and 2.11 (95% CI 0.78 to 5.68) in participants with confirmed AMI. While suggestive of harm, the small number of deaths recorded means that this could be a chance occurrence. Pain was measured by analgesic use. The pooled RR for the use of analgesics was 0.97 (95% CI 0.78 to 1.20).

AUTHORS' CONCLUSIONS

There is no conclusive evidence from randomised controlled trials to support the routine use of inhaled oxygen in people with AMI. A definitive randomised controlled trial is urgently required, given the mismatch between trial evidence suggestive of possible harm from routine oxygen use and recommendations for its use in clinical practice guidelines.

Paramedic Identification of Electrocardiograph J-Point and ST-Segments

Introduction:

Correct identification of the J-Point and ST-segment on an electrocardiograph (ECG) is an important clinical skill for paramedics working in acute healthcare settings. The skill of ECG analysis and interpretation is known to be challenging to learn and often is a difficult concept to teach.

Objectives:

The objective of the study was to determine if undergraduate paramedic students could accurately identify ECG ST-segment elevation and J-Point location.

Methods:

A convenience sample of undergraduate paramedic students (n = 148) was provided with four enlarged ECGs (ECG1–4) that illustrated different levels, patterns, and characteristics of ST-segment elevation. Participants were asked to identify whether ST-elevation was present, and if so, height in millimeters (mm) and the correct location of the J-Point.

Results:

There were significant variations in students'accuracy with both J-Point and ST-segment determination. Eleven (10%) students correctly identified the ST-segment being present in all ECGs. Also, ECG 2 reflected 6 mm of ST-elevation; however, only one student correctly identified this. Overall the students were 0.55 mm (95% CI = 0.29–0.81 mm, range = -6.5–5.8 mm) from the J-point on the horizontal and -0.18 mm (95% CI = -0.31–0.04 mm, range = -2.8–2.3 mm) on the vertical axis.

Conclusions:

Undergraduate paramedic students recognize ST-segment elevation. However, inaccuracies occurred with measurements of ST-segment and precise location of J-Points. Errors in ECG analysis may reflect weaknesses in teaching this skill. Consideration should be given to the design of an educational program that can reliably improve performance of this skill.

Novel biomarkers in diagnosing cardiac ischemia in the emergency department: a systematic review

BACKGROUND

Novel biomarkers of myocardial ischemia and inflammatory processes have the potential to improve diagnostic accuracy of acute coronary syndrome (ACS) within a shorter time interval after symptom onset.

OBJECTIVE

The objective was to review the recent literature and evaluate the evidence for use of novel biomarkers in diagnosing ACS in patients presenting with chest pain or symptoms suggestive of cardiac ischemia to the emergency department or chest pain unit.

METHODS

A literature search was performed in MEDLINE, EMBASE, Cochrane DSR, ACP Journal Club, DARE, CCTR, CMR, HTA, and NHSEED for studies from 2004 to 2010. We used the inclusion criteria: (1) human subjects, (2) peer-reviewed articles, (3) enrolled patients with ACS, acute myocardial infarction or undifferentiated signs and symptoms suggestive of ACS, and (4) English language or translated manuscripts. Two reviewers conducted a hierarchical selection and assessment using a scale developed by the International Liaison Committee on Resuscitation.

RESULTS

Out of a total 3194 citations, 58 articles evaluating 37 novel biomarkers were included for final review. Forty-one studies did not support the use of their respective biomarkers. Seventeen studies supported the use of 5 biomarkers, particularly when combined with cardiac-specific troponin: heart fatty acid-binding protein, ischemia-modified albumin, B-type natriuretic peptide, copeptin, and matrix metalloproteinase-9.

CONCLUSION

In patients presenting to the emergency department with chest pain or symptoms suggestive of cardiac ischemia, there is inadequate evidence to suggest the routine testing of novel biomarkers in isolation. However, several novel biomarkers have the potential to improve the sensitivity of diagnosing ACS when combined with cardiac-specific troponin.

Prehospital evaluation and economic analysis of different coronary syndrome treatment strategies--PREDICT--rationale, development and implementation

BACKGROUND

A standard of prehospital care for patients presenting with ST-segment elevation myocardial infarction (STEMI) includes prehospital 12-lead and advance Emergency Department notification or prehospital bypass to percutaneous coronary intervention centres. Implementation of either care strategies is variable across communities and neither may exist in some communities. The main objective is to compare prehospital care strategies for time to treatment and survival outcomes as well as cost effectiveness.

METHODS/DESIGN

PREDICT is a multicentre, prospective population-based cohort study of all chest pain patients 18 years or older presenting within 30 mins to 6 hours of symptom onset and treated with nitroglycerin, transported by paramedics in a number of different urban and rural regions in Ontario. The primary objective of this study is to compare the proportion of study subjects who receive reperfusion within the target door-to-reperfusion times in subjects obtained after four prehospital strategies: 12-lead ECG and advance emergency department (ED) notification or 3-lead ECG monitoring and alert to dispatch prior to hospital arrival; either with or without the opportunity to bypass to a PCI centre.

DISCUSSION

We anticipate four challenges to successful study implementation and have developed strategies for each: 1) diversity in the interpretation of the ethical and privacy issues across 47 research ethics boards/committees covering 71 hospitals, 2) remote oversight of data guardian abstraction, 3) timeliness of implementation, and 4) potential interference in the study by concurrent technological advances. Research ethics approvals from academic centres were obtained initially and submitted to non academic centre applications. Data guardians were trained by a single investigator and data entry is informed by a detailed data dictionary including variable definitions and abstraction instructions and subjected to error and logic checks. Quality oversight provided by a single investigator. The window of the trial in each community has been confirmed with the base-hospital medical director to correspond to the planned technological advances of the system of care. We hope this comparative analysis across treatment strategies for clinical outcomes and cost will provide sufficient evidence to implement the superior strategy across all communities and improve outcomes for all STEMI patients.

Oxygen therapy for acute myocardial infarction

BACKGROUND

Oxygen (O(2)) is widely recommended for patients with myocardial infarction yet a narrative review has suggested it may do more harm than good. Systematic reviews have concluded that there was insufficient evidence to know whether oxygen reduced, increased or had no effect on the heart ischaemia or infarct size.

OBJECTIVES

To review the evidence from randomised controlled trials to establish whether routine use of inhaled oxygen in acute myocardial infarction (AMI) improves patient-centred outcomes, in particular pain and death.

SEARCH STRATEGY

The following bibliographic databases were searched (to the end of February 2010): Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, MEDLINE In-Process, EMBASE, CINAHL, LILACS and PASCAL, British Library ZETOC, Web of Science ISI Proceedings. Experts were also contacted to identify any studies. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials of people with suspected or proven AMI, less than 24 hours after onset, in which the intervention was inhaled oxygen (at normal pressure) compared to air and regardless of co-therapies provided these were the same in both arms of the trial.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the titles and abstracts of identified studies to see if they met the inclusion criteria and independently undertook the data extraction. The quality of studies and the risk of bias were assessed according to guidance in the Cochrane Handbook. The primary outcomes were death, pain and complications. The measure of effect used was the relative risk (RR).

MAIN RESULTS

Three trials involving 387 patients were included and 14 deaths occurred. The pooled RR of death was 2.88 (95% CI 0.88 to 9.39) in an intention-to-treat analysis and 3.03 (95% CI 0.93 to 9.83) in patients with confirmed AMI. While suggestive of harm, the small number of deaths recorded meant that this could be a chance occurrence. Pain was measured by analgesic use. The pooled RR for the use of analgesics was 0.97 (95% CI 0.78 to 1.20).

AUTHORS' CONCLUSIONS

There is no conclusive evidence from randomised controlled trials to support the routine use of inhaled oxygen in patients with acute AMI. A definitive randomised controlled trial is urgently required given the mismatch between trial evidence suggestive of possible harm from routine oxygen use and recommendations for its use in clinical practice guidelines.

Prolonged closed cardiac massage using LUCAS device in out-of-hospital cardiac arrest with prolonged transport time

Saving more human lives through more effective reanimation measures is the goal of the new international guidelines on cardiopulmonary resuscitation as the decisive aspect for survival after cardiovascular arrest is that basic resuscitation should start immediately. According to the updated guidelines, the greatest efficacy in cardiac massage is only achieved when the right compression point, an adequate compression depth, vertical pressure, the correct frequency, and equally long phases of compression and decompression are achieved. The very highest priority is placed on restoring continuous circulation. Against this background, standardized continuous chest compression with active decompression has contributed to a favorable outcome in this case. The hydraulically operated and variably adjustable automatic Lund University Cardiac Arrest System (LUCAS) device (Jolife, Lund, Sweden) undoubtedly meets these requirements. This case report describes a 44-year-old patient who – approximately 15 min after the onset of clinical death due to apparent ventricular fibrillation – received cardiopulmonary resuscitation, initially by laypersons and then by the emergency medical team (manual chest compressions followed by situation-adjusted LUCAS compressions). Sinus rhythm was restored after more than 90 min of continuous resuscitation, with seven defibrillations. Interventional diagnostic workup did not reveal a causal morphological correlate for the condition on coronary angiography. After a 16-day period of hospital convalescence, with preventive implantation of an implantable cardioverter defibrillator and several weeks of rehabilitation, the patient was able to return home with no evidence of health impairment.

Influence of acute physical exercise on emerging muscular biomarkers

: Although there is comprehensive information on traditional biomarkers of muscle and cardiac damage following exercise, less is known on the kinetics of innovative markers, including ischemia modified albumin (IMA), glycogen phosphorylase isoenzyme BB (GPBB), carbonic anhydrase III (CAIII) and heart-type fatty acid-binding protein (H-FABP) in athletes performing a sub-maximal exercise.

: A total of 10 healthy trained Caucasian males performed a 21-km run. Blood samples were collected before the run, immediately after (post), 3, 6 and 24 h thereafter. Cardiac troponin I (cTnI), myoglobin, creatine kinase isoenzyme MB (CK-MB), GPBB, CAIII and H-FABP were assayed using a new diagnostic system based on protein biochip array technology. IMA was measured by a commercial colorimetric assay on a Roche Modular system P.

: Significant variations by one-way analysis of variance were observed for CK-MB (p=0.013), myoglobin (p<0.001), GPBB (p=0.029), H-FABP (p<0.001), CAIII (p=0.006), but not for cTnI (p=1.00) and IMA (p=0.881). In particular, values of all the biomarkers tested, but cTnI and IMA, increased significantly immediately after the run. GPBB and H-FABP values returned to baseline 6 and 3 h thereafter, those of CAIII, CK-MB and myoglobin remained significantly elevated from the pre-run value up to 24 h after the run. The major variation over pre-run values was recorded for myoglobin (nearly 4-fold increment), whereas CAIII, CK-MB, GPBB and H-FABP increased by 2.9-, 1.8-, 1.4- and 1.2-fold, respectively.

: We conclude that a sub-maximal aerobic exercise influences the concentration of several markers of muscle damage. Except for IMA, not one of the emerging biomarkers tested can be safely used to rule out myocardial damage as well as cardiospecific troponins in patients who had undergone recent physical activity.

Clin Chem Lab Med 2008;46:1313–8.

Compromising bradycardia: management in the emergency department

AIM OF THE STUDY

Bradycardia may represent a serious emergency. The need for temporary and permanent pacing is unknown.

METHODS

We analysed a registry for the incidence, symptoms, presenting rhythm, underlying mechanism, management and outcome of patients presenting with compromising bradycardia to the emergency department of a university hospital retrospectively during a 10-year period.

RESULTS

We identified 277 patients, 173 male (62%), median age 68 (IQR 58-78), median ventricular rate 33 min(-1) (IQR 30-40). The leading symptoms were syncope [94 (33%)], dizziness [61 (22%)], collapse [46 (17%)], angina [46 (17%)] and dyspnoea/heart failure [30 (11%)]. The initial ECG showed high grade AV block [134 (48%)], sinus bradycardia/AV block [46 (17%)], sinuatrial arrest [42 (15%)], bradycardic atrial fibrillation [39 (14%)] and pacemaker-failure [16 (6%)]. The underlying mechanisms were primary disturbance of cardiac automaticity and/or conduction [135 (49%)], adverse drug effect [58 (21%)], acute myocardial infarction [40 (14%)], pacemaker failure [16 (6%)], intoxication [16 (6%)] and electrolyte disorder [12 patients (4%)]. In 107 (39%) patients bed rest resolved the symptoms. Intravenous drugs to increase ventricular rate were given to 170 (61%) patients, 54 (20%) required additional temporary transvenous/transcutaneous pacing. Two severely intoxicated patients could be stabilised only by cardiopulmonary bypass. A permanent pacemaker was implanted in 137 patients (50%). Mortality was 5% at 30 days.

CONCLUSION

In our cohort, about 20% of the patients presenting with compromising bradycardia required temporary emergency pacing for initial stabilisation, in 50% permanent pacing had to be established.