e-Transmission of ECGs for expert consultation results in improved triage and treatment of patients with acute ischaemic chest pain by ambulance paramedics.

AIMS: In pre-hospital settings handled by paramedics, identification of patients with myocardial infarction (MI) remains challenging when automated electrocardiogram (ECG) interpretation is inconclusive. We aimed to identify those patients and to get them on the right track to primary percutaneous coronary intervention (PCI). METHODS AND RESULTS: In the Rotterdam-Rijnmond region, automated ECG devices on all ambulances were supplemented with a modem, enabling transmission of ECGs for online expert interpretation. The diagnostic protocol for acute chest pain was modified and monitored for 1 year. Patients with an ECG that met the criteria for ST-elevation myocardial infarction (STEMI) were immediately transported to a PCI hospital. ECGs that did not meet the STEMI criteria, but showed total ST deviation ≥800 µv were transmitted for online interpretation by the ECG expert. Online supervision was offered as a service if ECGs showed conduction disorders, or had an otherwise 'suspicious' pattern according to the ambulance paramedics. We enrolled 1,076 patients with acute ischaemic chest pain who did not meet the automated STEMI criteria. Their mean age was 63 years; 64% were men. After online consultation, 735 (68%) patients were directly transported to a PCI hospital for further treatment. PCI within 90 min was performed in 115 patients. CONCLUSION: During a 1-year evaluation of the modified pre-hospital triage protocol for patients with acute ischaemic chest pain, over 100 acute MI patients with an initially inconclusive ECG received primary PCI within 90 min. Because of these results, we decided to continue the operation of the modified protocol.

Coexistence of a bradycardia- and tachycardia-dependent bundle branch block.

Aberrant ventricular conduction is a rare phenomenon as compared with the more frequently occurring antrioventricular conduction disturbances. It leads to widening of the QRS complex, which is either due to a complete or functional block in one of the bundle branches or a block within the intramyocardial conduction system itself. Mechanisms that are potentially involved in the genesis of aberrant ventricular conduction are sudden shortening of cycle length (tachycardia-dependent phase III), antegrade block with retrograde concealed conduction, or bradycardia-dependent block (enhanced phase IV). In this paper, we present a patient with aberrant ventricular conduction with the occurrence of a tachycardia-dependent, as well as a bradycardia-dependent bundle branch block, which is an even rarer phenomenon.

[Percutaneous insertion of a left ventricular assist device for cardiogenic shock in a patient with a myocardial infarction]. / Percutaan ingebracht steunhart voor cardiogene shock bij een patiënt met een hartinfarct.

A 54-year-old man who was admitted due to cardiogenic shock as a result of a large anterior myocardial infarction 3 days previously was about to die, despite reperfusion therapy, application of an intra-aortic balloon pump, mechanical ventilation and maximal medical therapy. After insertion of a percutaneous left ventricular assist device, the patient was haemodynamically stable. After 11 days, the assist device was weaned and was removed. One day later, the patient died due to progressive heart failure. This case shows that a percutaneously inserted left ventricular assist device is effective in patients with severe, refractory cardiogenic shock, and is relatively simple to insert in the heart catheterisation room. However, it is still not clear what the recovery possibilities of the heart are following a large myocardial infraction, which factors may influence this recovery, and what the applicability of such a ventricular assist device might be in bridging the recovery period.

The clinical significance of whole blood viscosity in (cardio)vascular medicine.

Whole blood is a non-Newtonian fluid, which means that its viscosity depends on shear rate. At low shear, blood cells aggregate, which induces a sharp increase in viscosity, whereas at higher shear blood cells disaggregate, deform and align in the direction of flow. Other important determinants of blood viscosity are the haematocrit, the presence of macro-molecules in the medium, temperature and, especially at high shear, the deformability of red blood cells. At the sites of severe atherosclerotic obstructions or at vasospastic locations, when change of vessel diameter is limited, blood viscosity contributes to stenotic resistance thereby jeopardising tissue perfusion. However, blood viscosity plays its most important role in the microcirculation where it contributes significantly to peripheral resistance and may cause sludging in the postcapillary venules. Apart from the direct haemodynamic significance, an increase in blood viscosity at low shear by red blood cell aggregation is also associated with increased thrombotic risk, as has been demonstrated in atrial fibrillation. Furthermore, as increased red blood cell aggregation is a reflection of inflammation, hyperviscosity has been shown to be a marker of inflammatory activity. Thus, because of its potential role in haemodynamics, thrombosis and inflammation, determination of whole blood viscosity could provide useful information for diagnostics and therapy of (cardio)vascular disease.

Randomized study comparing cardiac response in endovascular and open abdominal aortic aneurysm repair.

BACKGROUND: The aim was to compare the cardiac response and the incidence of adverse cardiac events during and after endovascular (EVAR) and open (OR) repair of abdominal aortic aneurysms (AAAs). METHODS: Seventy-six patients with an AAA suitable for EVAR, and in a general condition allowing open surgery were randomized to EVAR (57 patients) or OR (19 patients). The analysis was on an intention-to-treat basis. Haemodynamic variables were assessed intraoperatively before, during and after aortic occlusion. During the procedure myocardial ischaemia was identified with use of electrocardiography (ECG) and transoesophageal echocardiography (TEE). After operation, cardiac complications were diagnosed by clinical observation, 12-lead ECG at 1 h, 1 day and 7 days, echocardiography at 1 month and measurement of cardiac enzymes. RESULTS: After aortic occlusion, a greater decrease in systemic vascular resistance compared with baseline was observed with OR than with EVAR (- 396 and - 70 dyne s/cm5 respectively; P = 0.03). The stroke work index, as a direct measure of myocardial performance, demonstrated a decrease during OR and an increase during EVAR during aortic occlusion (- 6.6 and + 1.7 g m/m2 respectively; P = 0.03) as well as after aortic occlusion (- 7.6 and + 3.4 g m/m2 respectively; P < 0.01), compared with baseline. The incidence of postoperative clinical cardiac complications was comparable in the two study groups; however, myocardial ischaemia, as observed by ECG and TEE, was observed more frequently in the OR group (ten of 19 versus 15 of 57 patients; P = 0.05). CONCLUSION: Haemodynamic changes were less severe and there was a lower incidence of myocardial ischaemia during EVAR than during OR. Studies are needed to demonstrate whether this may reduce the operative mortality rate.

Cardiac response and complications during endovascular repair of abdominal aortic aneurysms: a concurrent comparison with open surgery.

PURPOSE: The purpose of this study was to assess and to compare perioperative changes in left ventricular function and the incidence of adverse cardiac events in two groups of patients with abdominal aortic aneurysms, one during endovascular aneurysm repair (EAR) and the other during open aneurysm repair (OAR). METHODS: One hundred twenty consecutive patients who underwent EAR (49 patients) or OAR (71 patients) were prospectively studied. During the operation, the left ventricular function was assessed by the recording of the left ventricle stroke work index (SWI) and the cardiac index (CI) with a pulmonary artery catheter. Measurements were performed before, during, and after stent-graft deployment or aortic cross-clamping. Both maneuvers were defined as aortic occlusion (AO). Transesophageal echocardiography was performed to identify signs of wall motion abnormalities of the left ventricular wall, which indicated myocardial ischemia. Six-lead electrocardiograph monitoring was maintained until discharge from the intensive care unit. Postoperative cardiac complications were diagnosed by clinical observation, 12-lead ECG analysis at 1, 3, and 7 days after the operation, transthoracic echocardiography at 1 month, and measurement of cardiac enzymes. RESULTS: The two study groups were comparable with regard to most clinical aspects. The baseline myocardial performance was worse in patients who underwent EAR compared with patients who underwent OAR, as indicated by a reduced SWI (33.1 and 37.4, respectively; P =.03). During AO there was a comparable increase of the CI in both groups. However, after AO the rise in CI was higher in patients who underwent OAR compared with patients who underwent EAR (0.7 and 0.2, respectively; P <.01), representing a more pronounced hyperdynamic state. In addition, the SWI demonstrated a decrease in patients who underwent OAR compared with an increase in patients who underwent EAR during AO (-1.4 and +1.9, respectively; P =.04) and after AO (-0.9 and +2.6, respectively; P =.01). These findings represent more severe myocardial stress in patients who underwent OAR. The incidence of postoperative clinical cardiac adverse events was comparable in the two study groups. However, myocardial ischemia, as indicated by electrocardiography and transesophageal echocardiography, had a higher incidence in patients who underwent open surgery as compared with patients whose condition was managed endovascularly (57% and 33%, respectively; P =.01). CONCLUSION: Hemodynamic alterations during endovascular repair were not as severe as those in patients with open surgery and indicated less myocardial stress in the former category. These findings may explain a lower incidence of myocardial ischemia that was observed during endovascular repair. A lower frequency of clinical perioperative cardiac events in patients undergoing endovascular treatment may ultimately be expected.

[Endovascular abdominal aortic aneurysm repair. First experiences regarding 20 patients in Eindhoven]. / Endovasculaire behandeling van een aneurysma aortae abdominalis. Eerste ervaringen met 20 patiënten in Eindhoven.

OBJECTIVE: Evaluation of the early results of endovascular abdominal aortic aneurysm (AAA) repair. DESIGN: Prospective cohort study. SETTING: Catharina Hospital, Eindhoven, the Netherlands. METHODS: Operative results and complications following endovascular AAA repair in 20 consecutive patients were surveyed. The early results consisted of the procedural outcome and the events during a mean follow-up of 6.6 months (range: 1-12 months). Nine patients had a considerably increased operation risk (American Society of Anesthesiology (ASA) class III of IV). Criteria for success were absence of endoleak and of further expansion of the aneurysm. RESULTS: Three of the nine patients in bad general shape suffered an episode of cardiac failure after the operation. In the other patients there were no serious systemic complications. No patient died. Sixteen patients (80%) had a successful immediate AAA exclusion. In two patients a second endovascular procedure was required to seal an endoleak. In one patient the procedure was converted to an open reconstruction because of a persistent endoleak, while in another patient a small midgraft endoleak was treated conservatively. Ultimately 18 patients (90%) had a successful endovascular AAA repair. CONCLUSION: Endovascular AAA repair is feasible with a high success rate and a low complication rate. This method is expected to gain an important place in future AAA repair. Longer follow-up is needed to study late complications, among which occurrence of early and late endoleaks is the most important.

Blood loss and use of blood in internal mammary artery and saphenous vein bypass grafting with and without adding a single, low-dose of aprotinin (2 million units) to the pump prime.

In comparison with saphenous vein bypass grafting (SVG) without a pleurotomy, internal mammary artery (IMA) bypass surgery might enhance more blood loss by the intrathoracic wound and a wide opened pleura. Low-dose aprotinin (Trasylol) reduces blood loss and consequently, the use of homologous blood. We studied the blood loss and blood requirements peri-operatively in 70 patients, who underwent either SVG-(n = 35) or IMA-surgery (n = 35) without aprotinin and another 70 patients who underwent SVG- (n = 35) or IMA-surgery (n = 35) with a single dose of aprotinin, added to the pump prime. We also determined the hemoglobin and total protein content of the shed blood. Without aprotinin administration, the mean intra-operative and post-operative blood loss was significantly less (p < 0.01) in SVG-patients, than in IMA-patients. We observed no statistical differences in the mean blood requirements between SVG- and IMA-surgery (1.2 units and 1.6 units). The use of any homologous blood product was similarly averted in 39% of the SVG-patients, and in 48% of the IMA-patients. Treatment with aprotinin significantly lessened (p < 0.01) the mean intra-operative blood loss only in IMA-patients. Post-operative blood loss was diminished with 45% in IMA-patients and 33% in SVG-patients, being significantly less (p < 0.01) after SVG, than after IMA-surgery. Blood requirements were significantly lowered (p < 0.01): a total mean of 0.2 units in SVG- and 0.6 units in IMA-patients (NS). Any homologous blood product was prevented in 78% of the IMA-patients and in 87% of the SVG-patients (NS). The mean loss of hemoglobin and total protein per 100 ml of shed blood was similar in IMA-, and SVG-patients with or without aprotinin, although aprotinin diminished the total amounts in both groups with 50% (p < 0.01).