Mobile Coronary Care Unit Research Articles

Evolution of out-of-hospital emergency cardiac care: Heart attack therapy for a retired president helped modernize American emergency medical services

In the late 1960s, American emergency medical services (EMS) began to upgrade from mere Red Cross first aid to systems that now provide sophisticated advanced life support. This revolution in EMS stemmed from two pioneering Belfast reports in The Lancet that described how early out-of-hospital coronary care saved lives. Inspired, a handful of American physicians implemented avant-garde programs in the USA. One such physician, Richard Crampton of the University of Virginia, supported by the university and by Charlottesville–Albemarle Rescue Squad staffs, led an early effort to provide out-of-hospital drug treatment and defibrillation via a mobile coronary care unit (MCCU) ambulance. Half a dozen high-profile local cases, including successful treatment of retired President Lyndon B. Johnson, demonstrated MCCU efficacy to the Virginia and American public via local and national press coverage. The economic feasibility of the MCCU system was established. With two Virginia colleagues, Crampton successfully lobbied for a bill to permit trained nonphysicians to render out-of-hospital cardiac care with no on-site physician. This MCCU-augmented EMS system reduced coronary deaths in Charlottesville and Albemarle County, Virginia. It also stimulated nationwide progress in care by EMS systems that yielded countless lives saved in the succeeding half-century.

Effect of Military Conflicts on the Formation of Emergency Medical Services Systems Worldwide

This article briefly reviews the evolution of medical support during wars and conflicts from ancient to modern times and discusses the effect warfare has had on the development of civilian health care and emergency medical services (EMS). Medical breakthroughs and discoveries made of necessity during military conflicts have developed into new paradigms of medical care, including novel programs of triage and health assessment, emergency battlefield treatment and stabilization, anesthesia, and other surgical and emergency procedures. The critical role of organizations that provide proper emergency care to help the sick and injured both on the battlefield and in the civilian world is also highlighted.

Pre-hospital body surface potential mapping improves early diagnosis of acute coronary artery occlusion in patients with ventricular fibrillation and cardiac arrest

AimsTo determine whether 80-lead body surface potential mapping (BSPM) improves detection of acute coronary artery occlusion in patients presenting with out-of-hospital cardiac arrest (OHCA) due to ventricular fibrillation (VF) and who survived to reach hospital. Methods and resultsOf 645 consecutive patients with OHCA who were attended by the mobile coronary care unit, VF was the initial rhythm in 168 patients. Eighty patients survived initial resuscitation, 59 of these having had BSPM and 12-lead ECG post-return of spontaneous circulation (ROSC) and in 35 patients (age 69±13yrs; 60% male) coronary angiography performed within 24h post-ROSC. Of these, 26 (74%) patients had an acutely occluded coronary artery (TIMI flow grade [TFG] 0/1) at angiography. Twelve-lead ECG criteria showed ST-segment elevation (STE) myocardial infarction (STEMI) using Minnesota 9-2 criteria – sensitivity 19%, specificity 100%; ST-segment depression (STD) ≥0.05mV in ≥2 contiguous leads – sensitivity 23%, specificity 89%; and, combination of STEMI or STD criteria – sensitivity 46%, specificity 100%. BSPM STE occurred in 23 (66%) patients. For the diagnosis of TFG 0/1 in a main coronary artery, BSPM STE had sensitivity 88% and specificity 100% (c-statistic 0.94), with STE occurring most commonly in either the posterior, right ventricular or high right anterior territories. ConclusionAmong OHCA patients presenting with VF and who survived resuscitation to reach hospital, post-resuscitation BSPM STE identifies acute coronary occlusion with sensitivity 88% and specificity 100% (c-statistic 0.94).

Gavin James Brown

Gavin James Brown was born in Newcastle upon Tyne, where his father was a pre-National Health Service general practitioner working in a mining community with a heavy clinical workload. Gavin...

On the blindside of the ECG lies critical coronary disease

A 46-year-old man presented to the mobile coronary care unit following acute central chest pain radiating to his left arm at rest. He was seen out of hospital 7 min from onset of symptoms. He had suffered from inferior-territory ST-elevation myocardial infarction (STEMI) 3 years previously, with percutaneous intervention (PCI) to the right coronary artery (RCA). His only risk factor was a family history of ischaemic heart disease (his mother aged 42 years had coronary artery bypass grafting). At first medical contact, he was haemodynamically stable [blood pressure (BP) 112/76 mmHg] and clinical examination revealed no abnormality. Twelve-lead electrocardiogram (ECG) had 1 mm STE in aVR, ST-depression in I, II, aVF, V3–V6 and T-wave inversion in aVL (Figure 1a). Concomitant body surface potential mapping (BSPM), utilizing 80 surface electrodes, revealed high right anterior and posterior STEMIs with reciprocal lateral ST-depression (Figure 1b). …

Applying the concept of willingness to pay in the anesthetic management.

Willingness to pay (WTP) means the maximum amount of medical cost a patient is willing to pay to gain benefit or prevent any risk in medical care. This implies efficacy measuring the product of medical service by means of monetary units. Its initial application in healthcare was shown by Acton [1] in his analysis of cost-benefit from a differential amount of payments made to build mobile coronary care units to prevent the risk of death from heart attack. Tang et al [2] reported cost-effectiveness, cost-benefit and efficacy of medical cost in regards to the use of ondansetron for the prophylactic antiemetic for the ambulatory anesthetic patients.

Feasibility and long term outcome of home vs hospital initiated thrombolysis

Thrombolytic therapy improves mortality in acute myocardial infarction especially in those who receive treatment early. Pre-hospital therapy can reduce the time to treatment. Open, randomized study of patients with acute myocardial infarction of less than six hours duration in a rural community. Pre-hospital thrombolysis was administered using a mobile coronary care unit (MCCU) and all patients received IV streptokinase. Two-hundred and forty-eight patients were studied, 82 in the MCCU and 166 in the hospital group. The mean delay time to treatment was 136 minutes (MCCU group) and 196 minutes (hospital group) (p < 0.001). Reperfusion time was 116 minutes for the MCCU group and 118 minutes for the hospital group. Mortality at 30 days was 4.9% for the MCCU group and 15.7% for the hospital group (p = 0.014). Mortality at one year was 9.8% for the MCCU group and 23.5% for the hospital group (p = 0.009). Mortality for patients followed up to five years was 17.7% for the MCCU group and 35.2% for the hospital group (p = 0.005). There were no significant adverse events in either treatment group. Pre-hospital thrombolysis by MCCU is feasible and allows significant reduction in the delay time to treatment initiation. There are encouraging improvements in short- and long-term survival with no apparent reduction in safety profile.

High risk hypertensives: pre-hospital management of acute myocardial infarction—results from the French nationwide registry USIC 2000

Objective. – To assess the use of mobile coronary care units (MCU) in hypertensive patients previously treated for cardiovascular diseases in comparison with those with no history of cardiovascular disease and to estimate the influence of the use of MCU on cardiovascular outcome in this population. Patients. – We used a nationwide prospective registry of all patients admitted for AMI in French intensive care units in 2000. Patients without history of hypertension or patients admitted with pulmonary oedema or cardiogenic shock were excluded. Men (N = 514) and women (N = 291) were analysed separately . Results. – The proportion of patients with history of myocardial infarction, peripheral artery disease and stroke was not significantly higher in subjects who used physician-staffed MCU as compared with patients with no history of myocardial infarction, peripheral artery disease or stroke. In each sex, revascularization (pre hospital fibrinolysis, in hospital fibrinolysis or coronary angioplasty) were more frequent in patients who used MCU. Also, one year cardiovascular mortality was lower in men who used MCU. Conclusion. – known high risk hypertensive patients did not use physician-staffed MCU more than subjects free of such condition. Education of hypertensive patients at risk during routine visits is required to increase of the use of physician-staffed MCU in case of symptoms suggestive of AMI.

Percutaneous Coronary Intervention and 1-Year Survival in Patients Treated With Fibrinolytic Therapy for Acute ST-Elevation Myocardial Infarction

Aims To assess the predictors of 1 year mortality in patients treated with fibrinolytic therapy for ST-segment elevation myocardial infarction (STEMI) and to determine whether a strategy of early percutaneous coronary intervention (PCI) improves outcome. Methods and results Consecutive patients (n ¼ 474) admitted to our unit (1998–2001) with STEMI were treated with fibrinolytic therapy. For each patient, age, gender, admission via mobile coronary care unit (MCCU), infarct location, initial systolic blood pressure and Killip class, prior history of ischaemic heart disease, hypertension, diabetes mellitus, smoking status, family history, hyperlipidaemia, and in-hospital PCI (n ¼ 154) were recorded. Mortality at 1 year was obtained from medical records (n ¼ 473). Binary logistic regression analysis was performed to determine independent predictors of 1 year mortality. Mortality in the non-PCI group was 21 vs. 7% in the PCI group. Independent predictors of 1 year mortality were age (risk ratio 1.12, 95% CI 1.08–1.15, P , 0.0001), initial SBP � 80 mmHg (risk ratio 4.34, 95% CI 1.68–11.2, P ¼ 0.002), initial Killip class � 3 (risk ratio 2.97, 95% CI 1.42–6.2, P ¼ 0.004), and lack of in-hospital PCI (risk ratio 0.39, 95% CI 0.19–0.81, P ¼ 0.012). Although the PCI group were younger (P ¼ 0.007), more likely to be admitted via the MCCU (P ¼ 0.008), with a shorter pain to needle time (P ¼ 0.04), multivariable analysis adjusted for these differences. Conclusion In-hospital PCI in patients treated with fibrinolytic therapy for STEMI is associated with a substantial reduction in 1 year mortality.

Pre-hospital coronary care and coronary fatality in the Belfast and Glasgow MONICA populations

The aim of this study was to describe and compare coronary event case fatality and care pathways in two defined populations with access to different models of pre-hospital care provision. Secondary analysis of MONItoring of Trends and Determinants in CArdiovascular Disease (MONICA) population coronary event registers (1988, 1989, 1990, 1992 and 1993). Case fatality at 28 days following an acute coronary event was 6.5% greater in the Glasgow MONICA Project (GMP) population (46.7%) than in the Belfast MONICA Project (BMP) population (40.2%). Pre-hospital case fatality was 33.9% in the GMP population and 28.3% in the BMP population. These differences could not be fully explained by mobile coronary care unit (MCCU) responses in the BMP area. Initial care was provided in hospital for 28.3% of the BMP events and only 7.7% of the GMP events. Additional data collected by the Belfast and Glasgow MONICA investigators support a large difference between the median delay to main medical care in the BMP events (120 min) and the median delay to ward admission in the GMP area (220 min) at this time. Our findings suggest that the delay between coronary event onset and access to specialist coronary care was the most likely critical difference, irrespective of hospital-based MCCU provision in the BMP area. An established 'culture of early intervention' in Belfast may have been an important factor. As a large proportion of coronary event fatalities continue to occur outside hospital, there is a need to strengthen the evidence base underpinning the provision of appropriate skilled care and treatment at the earliest possible opportunity.

Percutaneous coronary intervention and 1 year survival in patients treated with fibrinolytic therapy for acute ST-elevation myocardial infarction

To assess the predictors of 1 year mortality in patients treated with fibrinolytic therapy for ST-segment elevation myocardial infarction (STEMI) and to determine whether a strategy of early percutaneous coronary intervention (PCI) improves outcome. Consecutive patients (n = 474) admitted to our unit (1998-2001) with STEMI were treated with fibrinolytic therapy. For each patient, age, gender, admission via mobile coronary care unit (MCCU), infarct location, initial systolic blood pressure and Killip class, prior history of ischaemic heart disease, hypertension, diabetes mellitus, smoking status, family history, hyperlipidaemia, and in-hospital PCI (n = 154) were recorded. Mortality at 1 year was obtained from medical records (n = 473). Binary logistic regression analysis was performed to determine independent predictors of 1 year mortality. Mortality in the non-PCI group was 21 vs. 7% in the PCI group. Independent predictors of 1 year mortality were age (risk ratio 1.12, 95% CI 1.08-1.15, P < 0.0001), initial SBP < or = 80 mmHg (risk ratio 4.34, 95% CI 1.68-11.2, P = 0.002), initial Killip class > or = 3 (risk ratio 2.97, 95% CI 1.42-6.2, P = 0.004), and lack of in-hospital PCI (risk ratio 0.39, 95% CI 0.19-0.81, P = 0.012). Although the PCI group were younger (P = 0.007), more likely to be admitted via the MCCU (P = 0.008), with a shorter pain to needle time (P = 0.04), multivariable analysis adjusted for these differences. In-hospital PCI in patients treated with fibrinolytic therapy for STEMI is associated with a substantial reduction in 1 year mortality.

Running the show

Faced with the closure of a mobile community coronary care unit, Annetta Quigley and Valerie McNiffe decided that nurses could keep it on the road

Diagnosing tachycardia

An 81-year-old lady was treated by a mobile coronary care unit for the sudden onset of chest pain and dyspnoea. She reported a myocardial infarction (MI) 5 years previously, but had been asymptomatic ever since. Her blood pressure was 180/100. Electrocardiographic (ECG) monitoring showed tachycardia, interpreted as a narrow complex tachycardia with retrograde P waves (arrows; figure 1). Intravenous adenosine failed to terminate the tachycardia. She was then given verapamil 5 mg intravenously and transported to an emergency room, where a 12-lead ECG (figure 2) was done.

Can we define patients with no and those with some chance of survival when found in asystole out of hospital?

We describe the epidemiology, prognosis, and circumstances at resuscitation among a consecutive population of patients with out-of-hospital cardiac arrest (OHCA) with asystole as the arrhythmia first recorded by the Emergency Medical Service (EMS), and identify factors associated with survival. We included all patients in the municipality of Göteborg, regardless of age and etiology, who experienced an OHCA between 1981 and 1997. There were a total of 4,662 cardiac arrests attended by the EMS during the study period. Of these, 1,635 (35%) were judged as having asystole as the first-recorded arrhythmia: 156 of these patients (10%) were admitted alive to hospital, and 32 (2%) were discharged alive. Survivors were younger (median age 58 vs 68 years) and had a witnessed cardiac arrest more often than nonsurvivors (78% vs 50%). Survivors also had shorter intervals from collapse to arrival of ambulance (3.5 vs 6 minutes) and the mobile coronary care unit (MCCU) (5 vs 10 min), and they received atropine less often on scene. There were also a greater proportion of survivors with noncardiac etiologies of cardiac arrest (48% vs 27%). Survivors to discharge also displayed higher degrees of consciousness on arrival to the emergency department in comparison to nonsurvivors. Multivariate analysis among all patients with asystole indicated age (p = 0.01) and witnessed arrest (p = 0.03) as independent predictors of an increased chance of survival. Multivariate analysis among witnessed arrests indicated short time to arrival of the MCCU (p <0.001) and no treatment with atropine (p = 0.05) as independent predictors of survival. Fifty-five percent of patients discharged alive had none or small neurologic deficits (cerebral performance categories 1 or 2). No patients >70 years old with unwitnessed arrests (n = 211) survived to discharge.

Cheating sudden death: how to do it, and what life's like after it.

Before the development of portable external defibrillators and the adoption of this technology by the emergency medical services, survival from out‐of‐hospital cardiac arrest was a very rare occurrence. Although CPR could be administered by ambulance crews, the delays involved in moving the victim to hospital prior to defibrillation were too great to allow many to survive. The first major advance in prehospital care occurred when Frank Pantridge addressed possible ways of reducing the high mortality rate associated with myocardial infarction. He recognized that most individuals who died did so within an hour of the onset of symptoms. Despite opposition from colleagues and the authorities, he and his resident, John Geddes, implemented the world's first mobile coronary care unit (MCCU) in Belfast in 1966. During the first 15 months of operation, the MCCU attended 10 patients who had ventricular fibrillation outside hospital, and all were successfully defibrillated.1 Soon after, MCCUs were introduced in many cities world‐wide, their main role being to transport victims of myocardial infarction quickly, and to provide defibrillation if needed. However, time was often wasted waiting for staff to arrive at the MCCUs prior to dispatch, and many cities had only a single MCCU serving a large geographic area. Response times were often slow, and those who had cardiac arrests before the MCCU arrived usually did not survive. The MCCU system was a breakthrough in prehospital care, but was limited by the concept that defibrillation had to be administered by a physician. The first move towards paramedic‐administered defibrillation occurred just 3 years after Pantridge's MCCU saved its first patient. Eugene Nagel, an emergency room physician from Miami, recognized the limitations of the MCCU system. Because of legal impediments which forbade paramedics from administering treatments other than first aid and CPR without orders from a physician, Nagel used …

Has an intensified treatment in the ambulance of patients with acute severe left heart failure improved the outcome?

The aim of this study was to evaluate short- and long-term outcome prior to and after the introduction of a more intensified treatment in the ambulance of patients with acute severe heart failure. Consecutive patients with acute severe heart failure transported by the mobile coronary care unit (MCCU) in the community of Göteborg prior to and after the introduction of an intensified treatment (nitroglycerine, continuous positive airway pressure (CPAP) and furosemide). One hundred and fifty-eight patients were evaluated during each period. The median age was 77 and 76.5 years, respectively, and 52% and 42% were women. The proportion of patients given nitroglycerine in the ambulance was 4% and 68% in the two periods; the proportion of patients treated with furosemide was 13% and 84%, respectively. CPAP was used in less than 1% during period 1 and in 91% during period 2. On admission of the ambulance 60% had fulminant pulmonary oedema during period 1 versus 78% during period 2 (p<0.0001). On admission to hospital the opposite was found, 93% during period 1 versus 76% during period 2 (p<0.0001). The median serum creatinine kinase (CK-MB) maximum activity was 13 microkat/l during period 1 and 8 microkat/l during period 2 (p = 0.007). However, the mortality during the first year remained high during both periods (39.2% and 35.8%, p = 0.64). It is concluded that a more intensive treatment in the ambulance of patients with acute severe heart failure seems to have resulted in an improvement in symptoms during transport and less myocardial damage. However, no significant improvement in long-term mortality was observed.

Diagnosis and risk stratification of patients with anginal pain and non-diagnostic electrocardiograms.

Patients with acute chest pain suggestive of myocardial ischaemia, and normal or non-diagnostic electrocardiograms, form a difficult subgroup for diagnosis and early risk stratification. We prospectively evaluated the role of troponin T (cTnT), troponin I (cTnI), CKMB mass and myoglobin, in the diagnosis and risk stratification of 214 patients with acute chest pain of < or = 24 h and non-diagnostic or normal ECGs admitted directly to the Cardiac Unit of the Royal Victoria Hospital Belfast from the Mobile Coronary Care Unit or the Accident/Emergency Department. This was a single-centre prospective study, and follow-up (3 months) was complete for all patients. Blood was assessed for quantitative cTnT, cTnI, CKMB mass and myoglobin, and qualitative cTnT on admission and at 12 h. Diagnosis of index event and incidence of new cardiac events (death, non-fatal myocardial infarction, revascularization, or readmission for unstable angina) over 3 months were assessed. Based on standard criteria, myocardial infarction occurred in 37/214 (17%), and unstable angina in 72/214 (34%). At 12 h from admission, cardiac troponins had higher sensitivity for the diagnosis of acute coronary syndromes (myocardial infarction and unstable angina) than conventional markers (cTnI 48%, cTnT 38%, CKMB mass 30% or myoglobin 27%). At 3 months, a new cardiac event had occurred in 42/214 (20%). Significantly higher event rates occurred when any of the biochemical markers was elevated, but the statistical significance was highest for patients with elevated cTnI (p < 0.0001). Whilst gender, history of ischaemic heart disease (IHD), stress test response, cTnT, cTnI, CKMB mass and myoglobin were univariate predictors, cTnI at 12 h and stress test response were the only two independent significant predictors for a subsequent cardiac event at 3 months. Raised cTnI at 12 h after admission had the highest sensitivity for the diagnosis of acute coronary syndromes, and was independently associated with a 2-3 times increased risk of future cardiac events within 3 months among patients with acute chest pain suggestive of myocardial ischaemia but with normal or non-diagnostic ECGs.

The Revolution and Evolution of Prehospital Cardiac Care

Prehospital cardiac care, first established in Belfast, Northern Ireland, in 1966, may be called revolutionary in that it was a radical break from existing practices. The Belfast program "moved" the coronary care unit into the community by treating the early complications of acute myocardial infarcation. The program staffed a mobile coronary care unit with a physician and nurse and demonstrated that patients with out-of-hospital sudden cardiac arrest could be resuscitated. The idea of prehospital cardiac care spread to other countries after publication of the Belfast experience in the Lancet. The first program in the United States, stationed at St Vincent's Hospital in New York, NY, began in 1968 and was modeled after the Belfast program. The physician-staffed model, however, was not widely imitated in the United States. Rather, beginning in 1969, programs using specially trained personnel, know as paramedics, began in Miami, Fla, Seattle, Wash, Columbus, Ohio, Los Angeles, Calif, Portland, Ore, and Nassau County, New York. Paramedic-staffed programs were designed not only to treat early complications of acute myocardial infarction, but also to attempt resuscitation for primary cardiac arrest. Most of the early paramedic programs were based in fire departments. Other programs used private ambulance or police personnel. Prehospital cardiac care has evolved significantly in the past 3 decades. Some notable developments include the tiered response system, training of the general public in cardiopulmonary resuscitation, low-energy defibrillators, automatic external defibrillators, and 12-lead electrocardiographic telemetry. The basic lesson of prehospital cardiac care is that the timely provision of cardiopulmonary resuscitation and defibrillation saves lives.

Hospital mortality after out-of-hospital cardiac arrest among patients found in ventricular fibrillation

The aim of this study was to describe factors associated with in-hospital mortality among patients being hospitalised after out-of-hospital cardiac arrest and who were found in ventricular fibrillation. The study was set in the community of Göteborg, Sweden. The subjects consisted of all patients who were hospitalised alive after out-of-hospital cardiac arrest, being reached by our mobile coronary care unit and who were found in ventricular fibrillation, between 1981 and 1992. In all, 488 patients fullfilled the inclusion criteria of which 262 (54%) died during initial hospitalization. In a multivariate analysis including age, sex, history of cardiovascular disease, chronic medication prior to arrest and circumstances at the time of arrest, the following appeared as independent predictors of hospital mortality: (1) interval between collapse and first defibrillation ( P < 0.001); (2) on chronic medication with diuretics ( P < 0.01); (3) age ( P < 0.01); (4) bystander initiated CPR ( P < 0.05); and (5) a history of diabetes ( P < 0.05). In a multivariate analysis considering various aspects of status on admission to hospital, the following were independently associated with death: (1) degree of consciousness ( P < 0.001) and (2) systolic blood pressure ( P < 0.05). In conclusion, among patients with out of hospital cardiac arrest found in ventricular fibrillation and being hospitalised alive, 54% died in hospital. The in-hospital mortality was related to patient characteristics before the cardiac arrest as well as to factors at the resuscitation itself.

Time delays to lytic therapy and outcome in 100 consecutive patients with a history suggestive of acute myocardial infarction in an area with access to a mobile coronary care unit

Time delays to fibrinolytic treatment and outcome were assessed in 100 consecutive patients, with suggestive symptoms and electrocardiographic changes of acute myocardial infarction, admitted to the coronary care unit of this hospital. All patients admitted from out-of-hospital had access to a mobile coronary care unit. Initially, 40 patients called a general practitioner, 30 called the '999' operator, 12 called the mobile coronary care unit, 10 reported directly to the Accident and Emergency Department, seven were in-hospital and one spoke to the general practitioner's receptionist. Subsequently, 59 patients were attended by the mobile coronary care unit, 34 were admitted via the Accident and Emergency Department and seven had symptoms in-hospital. Thrombolytic therapy was initiated in 45/59 (76%) patients by the mobile coronary care unit staff and in 29/34 (85%) patients in the Accident and Emergency Department by cardiac staff. The remaining 26 patients received thrombolytic treatment in the hospital coronary care unit or cardiac department. The mean (+/- SEM) time from symptom onset to the initiation of thrombolytic therapy was 127 (+/- 11 min) for those patients treated by the mobile coronary care unit staff and for those treated in the Accident and Emergency Department was 187 (+/- 13 min) (P = 0.005). Multiple regression analysis showed significant reductions in total time delay if patients received thrombolytic therapy by the mobile coronary care unit staff out-of-hospital, when chest pain began in-hospital, or if patients had a previous myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)