The current clinical practice for management of post-infarction ventricular septal rupture: a European survey.

Aims: Many historical and recent reports showed that post-infarction ventricular septal rupture (VSR) represents a life-threatening condition and the strategy to optimally manage it remains undefined. Therefore, disparate treatment policies among different centres with variable results are often described. We analysed data from European centres to capture the current clinical practice in VSR management. Methods and results: Thirty-nine centres belonging to eight European countries participated in a survey, filling a digital form of 38 questions from April to October 2022, to collect information about all the aspects of VSR treatment. Most centres encounter 1-5 VSR cases/year. Surgery remains the treatment of choice over percutaneous closure (71.8% vs. 28.2%). A delayed repair represents the preferred approach (87.2%). Haemodynamic conditions influence the management in almost all centres, although some try to achieve patients stabilization and delayed surgery even in cardiogenic shock. Although 33.3% of centres do not perform coronarography in unstable patients, revascularization approaches are widely variable. Most centres adopt mechanical circulatory support (MCS), mostly extracorporeal membrane oxygenation, especially pre-operatively to stabilize patients and achieve delayed repair. Post-operatively, such MCS are more often adopted in patients with ventricular dysfunction. Conclusion: In real-life, delayed surgery, regardless of the haemodynamic conditions, is the preferred strategy for VSR management in Europe. Extracorporeal membrane oxygenation is becoming the most frequently adopted MCS as bridge-to-operation. This survey provides a useful background to develop dedicated, prospective studies to strengthen the current evidence on VSR treatment and to help improving its currently unsatisfactory outcomes.

Coronary angiography in patients without ST-segment elevation following out-of-hospital cardiac arrest. COUPE clinical trial.

INTRODUCTION AND OBJECTIVES: The role of emergency coronary angiography (CAG) and percutaneous coronary intervention (PCI) following out-of-hospital cardiac arrest (OHCA) in patients without ST-segment elevation myocardial infarction (STEMI) remains unclear. We aimed to assess whether emergency CAG and PCI would improve survival with good neurological outcome in this population. METHODS: In this multicenter, randomized, open-label, investigator-initiated clinical trial, we randomly assigned 69 survivors of OHCA without STEMI to undergo immediate CAG or deferred CAG. The primary efficacy endpoint was a composite of in-hospital survival free of severe dependence. The safety endpoint was a composite of major adverse cardiac events including death, reinfarction, bleeding, and ventricular arrhythmias. RESULTS: A total of 66 patients were included in the primary analysis (95.7%). In-hospital survival was 62.5% in the immediate CAG group and 58.8% in the delayed CAG group (HR, 0.96; 95%CI, 0.45-2.09; P=.93). In-hospital survival free of severe dependence was 59.4% in the immediate CAG group and 52.9% in the delayed CAG group (HR, 1.29; 95%CI, 0.60-2.73; P=.4986). No differences were found in the secondary endpoints except for the incidence of acute kidney failure, which was more frequent in the immediate CAG group (15.6% vs 0%, P=.002) and infections, which were higher in the delayed CAG group (46.9% vs 73.5%, P=.003). CONCLUSIONS: In this underpowered randomized trial involving patients resuscitated after OHCA without STEMI, immediate CAG provided no benefit in terms of survival without neurological impairment compared with delayed CAG. CLINICALTRIALS: gov Identifier: NCT02641626.

Utility of pulmonary echography with a handheld ultrasound device in patients with acute coronary syndrome.

The objectives of this study are to establish the usefulness of lung ultrasound with a handheld device to predict the risk of developing heart failure with the need for mechanical ventilation (MV) in acute coronary syndrome (ACS). This is a prospective study of consecutive patients admitted because of ACS-type myocardial infarction, without data of HF at admission in a tertiary hospital, between February 2017 and February 2018. Lung ultrasounds were performed with a handheld cardiologic device in the first 24 h, and defined as echo-positive (PE+) when exams revealed 3 or more B-lines in 2 or more bilateral quadrants. We related this finding to the need for MV during admission. We included 119 patients (65.1 ± 12.8 year; 75.6% male, 24.4% female; 87.4% in Killip class I, 12.6% in Killip class II). Pulmonary echography was positive (PE+) in 21 patients (17.6%). The sensitivity of PE+ to predict MV was 93.3%, the specificity 93.3%, and the area under the curve 0.93. In Cox regression analysis adjusted by CRUSADE score and Killip class, PE+ patients had a hazard ratio of 64.55 (CI 7.87; 529.25, p < 0.001) of needing MV. PE+ was associated with more frequent use of inotropes and mortality. Pulmonary ultrasonography with a handheld echocardiograph was predictive of severe heart failure and the need for mechanical ventilation in ACS with high specificity and sensitivity.

Periodontitis and Other Risk Factors Related to Myocardial Infarction and Its Follow-Up.

The main issue in the prevention of myocardial infarction (MI) is to reduce risk factors. Periodontal disease is related to cardiovascular disease and both share risk factors. The purpose of this study is to investigate whether periodontitis can be considered a risk factor for MI and common risk factors in a case-control study and in a prospective follow-up study in patients with MI. The test group (MIG) was made up of 144 males who had MI in the previous 48 h. The control group (CG) was composed of 138 males without MI. Both groups were subdivided according to the presence or absence of stage III and IV of periodontitis. General data; Mediterranean diet and physical activity screening; periodontal data; and biochemical, microbiological and cardiological parameters were recorded. ANOVA, Mann-Whitney U and Kruskal-Wallis statistical tests and binary logistic regression analysis were applied. No differences in anthropometric variables were observed between the four groups. The average weekly exercise hours have a higher value in CG without periodontitis. The number of leukocytes was higher in MIG, the number of monocytes was higher in CG and the number of teeth was lower in MIG with periodontitis. Adherence to the Mediterranean diet was higher in CG. Porphyromonas gingivalis and Tannerella forsythia were higher in CG with periodontitis and in MIG with and without periodontitis. At follow-up, the left ventricular ejection fraction (LVEF) data were better in the non-periodontitis group: 15 patients had Mayor Cardiovascular Adverse Events (MACE), 13 of them had periodontitis and 2 did not show periodontitis. Periodontitis, exercise, diet and smoking are risk factors related to MI. MACE presented in the 'MI follow-up' shows periodontitis, weight, exercise hours and dyslipidemia as risk factors. LVEF follow-up values are preserved in patients without periodontitis. Our data suggest that periodontitis can be considered a risk factor for MI and MACE in the studied population.

Intravenous metoprolol during ongoing STEMI ameliorates markers of ischemic injury: a METOCARD-CNIC trial electrocardiographic study.

Besides its protective effect against neutrophil-mediated injury at reperfusion, intravenous (IV) metoprolol was recently shown to reduce the progression of ischemic injury in a pig model of ST-segment elevation myocardial infarction (STEMI). Here, we tested the hypothesis that IV metoprolol administration in humans with ongoing STEMI blunts the time­dependent progression of ischemic injury assessed by serial electrocardiogram (ECG) evaluations before reperfusion. The METOCARD-CNIC trial randomized 270 anterior STEMI patients to IV metoprolol or control before reperfusion by percutaneous coronary intervention (PCI). In 139 patients (69 IV metoprolol, 70 controls), two ECGs were available (ECG-1 before randomization, ECG-2 pre-PCI). Between-group ECG differences were analyzed using univariate and multivariate regression models. No significant between-group differences were observed on ECG-1. On ECG-2, patients who received IV metoprolol had a narrower QRS than those in the control group (84 ms vs. 90 ms, p = 0.029), a lower prevalence of QRS distortion (10% vs. 26%, p = 0.017), and a lower sum of anterior and total ST-segment elevation (10.1 mm vs. 13.6 mm, p = 0.014 and 10.4 mm vs. 14.0 mm, p = 0.015, respectively). Adjusted analysis revealed similar results. Significant associations were observed between ECG-2 variables and cardiac magnetic resonance imaging measurements (extent of myocardial edema, infarct size, microvascular obstruction, and left-ventricular ejection fraction) after STEMI. In summary, IV metoprolol administration before reperfusion ameliorates ECG markers of myocardial ischemia in anterior STEMI patients. These data confirm that IV metoprolol is able to reduce ischemic injury and highlight the ability of ECG analysis to provide relevant real-time information on the effect of cardioprotective therapies before reperfusion.

Dexmedetomidine in medical cardiac intensive care units. Data from a multicenter prospective registry.

BACKGROUND: Dexmedetomidine induces cooperative and arousable sedation. Our aim was to analyze dexmedetomidine use in medical cardiac intensive care units (CICU). METHODS: Multicenter prospective registry of patients treated with dexmedetomidine in CICU. Consecutive inclusion during a 12-month period. RESULTS: A total of 410 patients were included, mean age was 67.4 ± 13.9 years, and 94 (22.9%) were women. Before using dexmedetomidine, 247 patients (60.2%) had delirium, 48 developed delirium after dexmedetomidine use. In 178 (43.4%) dexmedetomidine was used during weaning from mechanical ventilation, with a reintubation rate of 10.1%, early reintubation rate (<24 h) 1.7%. Seventy-seven patients (18.8%) died during admission. Dexmedetomidine mean dose infusion was 0.51 ± 0.25 µ/kg/h, during a median of 34 h (interquartile range 12-78 h). Three hundred forty-eight patients received adjuvant sedatives (84.9%). Sixty-eight patients (16.6%) had adverse effects. The most frequent adverse effects were hypotension with systolic blood pressure <80 mmHg (44 patients - 10.7%), bradycardia <40 beats per minute (15 patients - 3.7%), and both bradycardia and hypotension (4 patients - 1.0%). Patients with adverse effects received more frequently inotropes (53 [81.6%] vs. 212 [65.4%], p = 0.02) and fewer adjuvant sedatives (49 [75.4%] vs. 282 [87.0%], p = 0.01). The independent predictors of adverse effects were inotropes use (odds ratio [OR] 2.73, 95% confidence interval [CI] 1.30-5.74, p = 0.008) and lack of adjuvant sedatives (OR 3.03, 95% CI 1.49-6.26, p = 0.002). CONCLUSION: Dexmedetomidine safety for medical CICU patients seems to be similar to that for general intensive care unit patients. Inotropes and lack of adjuvant sedatives were associated with adverse effects.

QRS distortion in pre-reperfusion electrocardiogram is a bedside predictor of large myocardium at risk and infarct size (a METOCARD-CNIC trial substudy).

BACKGROUND: QRS distortion is an electrocardiographic (ECG) sign of severe ongoing ischemia in the setting of ST-segment elevation acute myocardial infarction (STEMI). We sought to evaluate the association between the degree of QRS distortion and myocardium at risk and final infarct size, measured by cardiac magnetic resonance (CMR). METHODS: A total of 174 patients with a first anterior STEMI reperfused by primary angioplasty were prospectively recruited. Pre-reperfusion ECG was used to divide the study population into three groups according to the absence of QRS distortion (D0) or its presence in a single lead (D1) or in 2 or more contiguous leads (D2+). Myocardium at risk and infarct size were determined by CMR one week after STEMI. Multiple regression analysis was used to study the association of QRS distortion with myocardium at risk and infarct size, with adjustment for relevant clinical and ECG variables. RESULTS: 101 patients (58%) were in group D0, 30 (17%) in group D1, and 43 (25%) in group D2+. Compared with group D0, presence of QRS distortion (groups D2+ and D1) was associated with a significantly adjusted larger extent of myocardium at risk (group D2+: absolute increase 10.4%, 95% CI 6.1-14.8%, p<0.001; group D1: absolute increase 3.3%, 95% CI 1.3-7.9%, p=0.157) and larger infarct size (group D2+: absolute increase 10.1%, 95% CI 5.5-14.7%, p<0.001; group D1: absolute increase 4.9%, 95% CI 0.08-9.8%, p=0.046). CONCLUSIONS: Distortion in the terminal portion of the QRS complex on pre-reperfusion ECG in two or more leads is independently associated with larger myocardium at risk and infarct size in the setting of primary angioplasty-reperfused anterior STEMI. QRS distortion in only one lead is independently associated with larger infarct size in this setting. Our findings suggest that QRS distortion analysis could be included in risk-stratification of patients presenting with anterior STEMI.

Influence of the previous use of ß-blockers on the early clinical course of acute coronary syndromes.

Recent studies have recently questioned the current role of ß-blockers in myocardial infarction. Our purpose is to analyze the influence of the previous use of ß-blockers on the early course of patients admitted because of acute coronary syndrome (ACS). We analyzed the data of 37.359 patients included in the ARIAM-Andalucia Registry. Of them, 7759 (20.8%) were previously receiving ß-blockers. BB patients were older, more often female, had more risk factors and vascular disease, and less often had an ST-elevation myocardial infarction. In the unadjusted analysis, BB patients less often had ventricular fibrillation or atrioventricular block, and more often a Killip classification >1, and no difference of in-hospital mortality (5.7 vs 5.6%). After logistic regression analysis and propensity score matching, no differences in complications or mortality (odds ratio 0.997, 95% confidence interval 0.882-1.128) were found in relationship to previous ß-blockers. In conclusion, we find that the previous administration of ß-blockers is not an independent predictor of the early prognosis of ACS.

ECG de noviembre de 2014 / ECG, November 2014

No disponible

Prehospital activation of cardiac catheterization teams in ST-segment elevation myocardial infarction.

INTRODUCTION AND OBJECTIVES: Current clinical guidelines for ST-segment elevation myocardial infarction (STEMI) suggest prehospital activation of the cardiac catheterization team. In previous protocols in our center activation occurred once patients arrived at the hospital. In January 2011, we initiated a new primary angioplasty activation protocol from prehospital locations. Our objective was to quantify the influence of this change on reperfusion times. METHODS: A total of 173 consecutive STEMI patients (n=73/100 before/after initiation of the new protocol), diagnosed in a prehospital setting within 12 hours of symptom onset, were analyzed. The time between the patient's arrival at the hospital and beginning of the angioplasty procedure was termed the cath lab activation delay. RESULTS: The new protocol resulted in a 37-min reduction in system delay (166 [132-235] min before vs. 129 [105-166] min after, p<0.001), mostly driven by a 64% reduction in cath lab activation delay (55 [0-79] min before vs. 20 [0-54] min after, p=0.001). This reduction was mainly observed outside working hours. The percentage of patients treated with a system delay ≤ 120 min increased from 14.5% before the new protocol to 41.8% afterwards (p=0.001). CONCLUSIONS: Prehospital activation of the cardiac catheterization team resulted in earlier reperfusion of STEMI patients.

The previous use of digoxin does not worsen early outcome of acute coronary syndromes: an analysis of the ARIAM Registry.

The aim of the study was to determine the influence of the previous use of digoxin on the hospital mortality and complications of patients admitted because of acute coronary syndrome (ACS). We analyzed the data of patients included in the ARIAM-Andalucia Registry, which involves 49 hospitals in Andalucia, Spain, from 2007 to 2012. Patients on digoxin treatment prior to their admission because of ACS constituted the digoxin group (DG), and were compared with the group of patients not on digoxin. Logistic regression and propensity score matching were used to analyze the differences. We included 20,331 patients, of whom 244 (1.2%) were on digoxin. DG patients were older (73.1 vs 63.7 years old), more often women, and had more diabetes, hypertension, previous myocardial infarction, heart failure, stroke, atrial fibrillation, peripheral vascular disease, obstructive pulmonary disease or kidney disease. On univariate analysis, DG patients had significantly higher hospital mortality (13.5 vs 5.3% P < 0.001), and more cardiogenic shock, but less ventricular fibrillation, and no differences in atrioventricular block, stroke or reinfarction. After the multivariate analysis, DG had no significant influence on hospital prognosis [odds ratio (OR) 1.21, 95% confidence interval 0.79-1.86]. The analysis of a propensity-matched cohort of 464 patients (232 DG and 232 NoDG) did not find differences in hospital mortality (13.4 vs 13.4%) nor other complications. In our cohort of ACS patients, the previous treatment with digoxin was not associated with an increase in dysrhythmic complications nor was an independent predictor of mortality during hospitalization.

Study design for the "effect of METOprolol in CARDioproteCtioN during an acute myocardial InfarCtion" (METOCARD-CNIC): a randomized, controlled parallel-group, observer-blinded clinical trial of early pre-reperfusion metoprolol administration in ST-segment elevation myocardial infarction.

BACKGROUND: Infarct size predicts post-infarction mortality. Oral ß-blockade within 24 hours of a ST-segment elevation acute myocardial infarction (STEMI) is a class-IA indication, however early intravenous (IV) ß-blockers initiation is not encouraged. In recent magnetic resonance imaging (MRI)-based experimental studies, the ß(1)-blocker metoprolol has been shown to reduce infarct size only when administered before coronary reperfusion. To date, there is not a single trial comparing the pre- vs. post-reperfusion ß-blocker initiation in STEMI. OBJECTIVE: The METOCARD-CNIC trial is testing whether the early initiation of IV metoprolol before primary percutaneous coronary intervention (pPCI) could reduce infarct size and improve outcomes when compared to oral post-pPCI metoprolol initiation. DESIGN: The METOCARD-CNIC trial is a randomized parallel-group single-blind (to outcome evaluators) clinical effectiveness trial conducted in 5 Counties across Spain that will enroll 220 participants. Eligible are 18- to 80-year-old patients with anterior STEMI revascularized by pPCI ≤6 hours from symptom onset. Exclusion criteria are Killip-class ≥III, atrioventricular block or active treatment with ß-blockers/bronchodilators. Primary end point is infarct size evaluated by MRI 5 to 7 days post-STEMI. Prespecified major secondary end points are salvage-index, left ventricular ejection fraction recovery (day 5-7 to 6 months), the composite of (death/malignant ventricular arrhythmias/reinfarction/admission due to heart failure), and myocardial perfusion. CONCLUSIONS: The METOCARD-CNIC trial is testing the hypothesis that the early initiation of IV metoprolol pre-reperfusion reduces infarct size in comparison to initiation of oral metoprolol post-reperfusion. Given the implications of infarct size reduction in STEMI, if positive, this trial might evidence that a refined use of an approved inexpensive drug can improve outcomes of patients with STEMI.

Can resistance to aspirin be reversed after an additional dose?

Aspirin resistance or aspirin non-responsiveness is a recently described phenomenon which has been consistently associated with an increased risk of cardiovascular events. This study was designed to determine the effects of an additional dose of 100 mg of aspirin on platelet function and proportion of aspirin non-responders using the platelet function analyzer-100 (PFA-100), in a well characterized population of stable coronary heart disease patients already on long-term aspirin treatment. Platelet function was assessed using PFA-100 in 141 patients (64.8 ± 10.1 years, 87.9% men) on long-term aspirin treatment (100 mg/day) before and 1 h after "in site" oral aspirin administration (100 mg). Prevalence of aspirin non-responders using PFA-100 was 50.7% (95% confidence interval 42.4-59). One hour after 100 mg of oral aspirin, reassessment of aspirin effects showed a prevalence of non-responders using PFA of 35.0% (95% CI 27.3-43.2) (P < 0.001 vs. pre-dose proportion). Using the PFA-100 system, reassessment of platelet function following oral administration of daily aspirin dosage significantly reduces the number of stable coronary disease patients considered to be non-responders to such treatment.

Circadian variations of infarct size in acute myocardial infarction.

BACKGROUND: The circadian clock influences a number of cardiovascular (patho)physiological processes including the incidence of acute myocardial infarction. A circadian variation in infarct size has recently been shown in rodents, but there is no clinical evidence of this finding. OBJECTIVE: To determine the impact of time-of-day onset of ST segment elevation myocardial infarction (STEMI) on infarct size. METHODS: A retrospective single-centre analysis of 811 patients with STEMI admitted between 2003 and 2009 was performed. Infarct size was estimated by peak enzyme release. The relationship between peak enzyme concentrations and time-of-day were characterised using multivariate regression splines. Time of STEMI onset was divided into four 6-hour periods in phase with circadian rhythms. RESULTS: Model comparisons based on likelihood ratio tests showed a circadian variation in infarct size across time-of-day as evaluated by peak creatine kinase (CK) and troponin-I (TnI) concentrations (p=0.015 and p=0.012, respectively). CK and TnI curves described similar patterns across time, with a global maximum in the 6:00-noon period and a local minimum in the noon-18:00 period. Infarct size was largest in patients with STEMI onset in the dark-to-light transition period (6:00-noon), with an increase in peak CK and TnI concentrations of 18.3% (p=0.031) and 24.6% (p=0.033), respectively, compared with onset of STEMI in the 18:00-midnight period. Patients with anterior wall STEMI also had significantly larger infarcts than those with STEMI in other locations. CONCLUSIONS: Significant circadian oscillations in infarct size were found in patients according to time-of-day of STEMI onset. The infarct size was found to be significantly larger with STEMI onset in the dark-to-light transition period (6:00-noon). If confirmed, these results may have a significant impact on the interpretation of clinical trials of cardioprotective strategies in STEMI.

Resultados de un programa mixto de implantación de prótesis aórtica por vía transfemoral con los dispositivos de Edwards y CoreValve / Findings of a mixed transfemoral aortic valve implantation program using edwards and CoreValve devices

Introducción y objetivos. La implantación de prótesis valvular aórtica por vía transfemoral con los dispositivos Edwards-SAPIEN (ES) y Medtronic-CoreValve (MCV) es una alternativa al reemplazo quirúrgico en pacientes con estenosis aórtica severa y alto riesgo quirúrgico. Nuestro objetivo es comparar los resultados obtenidos con uno y otro dispositivo. Métodos. Estudio prospectivo de las prótesis implantadas por vía transfemoral en nuestro centro. Resultados. De los 76 pacientes (edad, 83±6 años; el 63% mujeres; EuroSCORE logístico, 18±9), Se seleccionó a 50 para ES y a 26 para MCV. No se observaron diferencias entre grupos en edad, sexo, clase funcional, área valvular, enfermedades asociadas o EuroSCORE. Se consiguió implantar la prótesis en el 84% del grupo ES y el 100% del grupo MCV (p=0,04); hubo 3 casos de taponamiento, 2 disecciones aórticas y 1 malposición en la serie ES. Las complicaciones vasculares fueron similares (el 26 frente al 23%), pero la necesidad de marcapasos fue mayor con la MCV (el 10 frente al 39%; p=0,003). Las mortalidades totales a 30 días fueron del 12 y el 20% (sin diferencia significativa) y a 1 año, del 24 y el 20% en los grupos ES y MCV respectivamente. Tras un seguimiento de 367±266 días para ES y 172±159 para MCV, 3 pacientes fallecieron; los demás mantienen la mejoría clínica y no se observan cambios ecocardiográficos. Conclusiones. La mortalidad hospitalaria, la tasa de complicaciones y la evolución a medio plazo han sido similares con ambos dispositivos; las únicas diferencias encontradas han sido una tasa de implantación con éxito mayor con la MCV, aunque a expensas de una mayor frecuencia de bloqueo auriculoventricular (AU)

Introduction and objectives: Transfemoral implantation of an Edwards SAPIEN (ES) or Medtronic CoreValve (MCV) aortic valve prosthesis is an alternative to surgical replacement for patients with severe aortic stenosis and a high surgical risk. The study’s aim was to compare results obtained with these two devices. Methods: Prospective observational study of transfemoral prosthesis implantation performed at our center. Results: Of the 76 patients (age 83 +/- 6 years, 63% female, logistic EuroSCORE 18 +/- 9) included, 50 were assigned the ES and 26 the MCV device. There was no difference between the groups in age, sex, functional class, valve area, associated conditions, or EuroSCORE. Implantation was successful in 84% of the ES group and 100% of the MCV group (P = .04). There were three cases of tamponade, two aortic dissections and one valve malposition in the ES group. The two groups had similar vascular access complication rates (26% vs. 23%; P = NS), but pacemaker need was greater with the MCV (10% vs. 39%; P = .003). Mortality rates at 30 days were 12% and 20% (P = NS) in the ES and MCV groups, respectively, and at 1 year, 24% and 20% (P = NS), respectively. After a follow-up of 367 +/- 266 days in the ES group and 172 +/- 159 days in the MCV group, three patients died. Clinical improvement was maintained in other patients and no echocardiographic changes were observed. Conclusions: In-hospital mortality, the complication rate and medium-term outcomes were similar with the two devices. The only difference observed was a higher implantation success rate with the MCV, although at the expense of a greater frequency of atrioventricular block (AU)

Systemic fibrinolysis through intraosseous vascular access in ST-segment elevation myocardial infarction.

In emergency situations, intraosseous cannulation represents an alternative route of vascular access when peripheral vein insertion is difficult. We present the first documented case of intraosseous systemic fibrinolysis in a patient with ST-segment elevation myocardial infarction. In this case, repetitive episodes of ventricular fibrillation occurred soon after first contact with emergency care providers. Given that the patient had difficult peripheral venous access, an intraosseous catheter was inserted. Fibrinolytics and antiarrhythmic drugs were administered though this line, resulting in resolution of coronary ischemia and electrical instability, without complications. Intraosseous cannulation represents a novel route for administration of systemic fibrinolysis in cases of difficult peripheral venous access in the out-of-hospital setting.

Profound myocardial ischemia associated to occlusion of the right coronary artery.

A 75-year-old man with hypertension, hypercholesterolemia and history of coronary artery disease was admitted to the hospital because of sudden loss of consciousness. The patient suffered an acute myocardial infarction seven years before this admission, which was treated with percutaneous transluminal coronary angioplasty and stent implantation in the right coronary artery. The initial electrocardiogram showed a complete atrioventricular block, with narrow ventricular complexes at a rate of 40 bpm. The next electrocardiogram, obtained after the administration of atropine, showed a sinus rhythm at 84 bpm with first-degree atrioventricular block, obvious ST-segment elevation on leads II, III, aVF, V3 to V6, and electrical alternation of the ST-segment. Subsequently, he suffered three episodes of ventricular fibrillation which were successfully defibrillated. The ST-segment elevation improved after sublingual nitroglycerine and the patient underwent urgent coronary angiography, which showed a critical stenosis in the middle part of the right coronary artery with a lot of thrombus material in the site of the previous stent. The rest of the coronary arteries did not reveal significant lesions. Thrombus aspiration and balloon angioplasty were successfully performed without residual stenosis. The ST-elevation alternans is a rare phenomenon which was initially described in the setting of coronary artery spasm. It is believed to be associated to profound myocardial ischemia, particularly in relation with occlusions of the left anterior descending coronary artery, and to the occurrence of malignant ventricular arrhythmia and sudden cardiac death.