Cardiac remodelling: concentric versus eccentric hypertrophy in strength and endurance athletes.

Cardiac remodelling is commonly defined as a physiological or pathological state that may occur after conditions such as myocardial infarction, pressure overload, idiopathic dilated cardiomyopathy or volume overload. When training excessively, the heart develops several myocardial adaptations causing a physiological state of cardiac remodelling. These morphological changes depend on the kind of training and are clinically characterised by modifications in cardiac size and shape due to increased load. Several studies have investigated morphological differences in the athlete's heart between athletes performing strength training and athletes performing endurance training. Endurance training is associated with an increased cardiac output and volume load on the left and right ventricles, causing the endurance-trained heart to generate a mild to moderate dilatation of the left ventricle combined with a mild to moderate increase in left ventricular wall thickness. Strength training is characterised by an elevation of both systolic and diastolic blood pressure. This pressure overload causes an increase in left ventricular wall thickness. This may or may not be accompanied by a slight raise in the left ventricular volume. However, the development of an endurancetrained heart and a strength-trained heart should not be considered an absolute concept. Both forms of training cause specific morphological changes in the heart, dependent on the type of sport. (Neth Heart J 2008;16:129-33.).

The future of cardiovascular imaging and non-invasive diagnosis: a joint statement from the European Association of Echocardiography, the Working Groups on Cardiovascular Magnetic Resonance, Computers in Cardiology, and Nuclear Cardiology, of the European Society of Cardiology, the European Association of Nuclear Medicine, and the Association for European Paediatric Cardiology.

Advances in medical imaging now make it possible to investigate any patient with cardiovascular disease using multiple methods which vary widely in their technical requirements, benefits, limitations, and costs. The appropriate use of alternative tests requires their integration into joint clinical diagnostic services where experts in all methods collaborate. This statement summarises the principles that should guide developments in cardiovascular diagnostic services.

Cardiac remodeling after myocardial infarction is impaired in IGF-1 deficient mice.

OBJECTIVE: To obtain more insight in the role of IGF-1 in cardiac remodeling and function after experimental myocardial infarction. We hypothesized that cardiac remodeling is altered in IGF-1 deficient mice, which may affect cardiac function. METHODS: A myocardial infarction was induced by surgical coronary artery ligation in heterozygous IGF-1 deficient mice. One week after surgery, left ventricular function was analyzed, and parameters of cardiac remodeling were measured. RESULTS: No significant difference in cardiac function was found between infarcted wildtype and knock-out animals, despite a marked reduction in capillarization and blunting of the hypertrophic response of the interventricular septum in the IGF-1 deficient group. Furthermore, decreased DNA synthesis and increased apoptosis rates were observed in the IGF-1 knock-out mice. CONCLUSION: IGF-1 deficient mice show preservation of cardiac function 1 week after MI, despite an altered cardiac remodeling process.

Right ventricular support for off-pump coronary artery bypass grafting studied with bi-ventricular pressure--volume loops in sheep.

OBJECTIVES: Tilting the heart during off-pump coronary artery bypass grafting (OPCABG) causes a strong decrease in cardiac output. It is hypothesized that this decrease is caused by reduced right ventricular filling and that right ventricular support is thus the best way to restore cardiac output. Simultaneous left and right ventricular pressure-volume loops were used to test this hypothesis. METHODS: In seven sheep, the heart was tilted with the use of an Octopus device. After unsupported tilting, a novel right ventricular support, the Enabler, was activated at a pulsatile flow of 1.6 l/min. Pressure-volume loops of both ventricles were obtained using conductance catheters, and cardiac output was monitored with an aortic flow probe. RESULTS: Tilting reduced cardiac output by 31% (4.4--3.1 l/min, P=0.001) and right ventricular end-diastolic volume by 44% (86--51 ml, P=0.005), while right ventricular end-diastolic pressure did not decrease. Left ventricular systolic pressure was not significantly reduced upon tilting and even increased in two animals. During Enabler right ventricular support, the cardiac output remained 23% lower than pre-tilting values (3.4 vs. 4.4 l/min, P=0.001). CONCLUSIONS: Restricted right ventricular filling is the primary cause of the strong decrease in cardiac output during tilting. The Enabler right ventricular support can currently not restore cardiac output to pre-tilting values, mainly caused by its limited output and a decrease in right ventricular output upon Enabler activation. Constant monitoring of cardiac output is crucial during (unsupported or supported) tilting as blood pressure alone may not reflect the extent of the reduction in cardiac function.

Angiographic assessment of prospectively determined non-invasive reperfusion indices in acute myocardial infarction.

OBJECTIVE: To investigate the value of non-invasive reperfusion indices in acute myocardial infarction, avoiding the possible need for acute coronary angiography and subsequent angioplasty. DESIGN: In a prospective angiographic study, seven potential ECG or clinical markers of reperfusion were analysed in 230 patients with acute myocardial infarction. In all patients two 12 lead ECGs were used: the ECG on admission and the ECG immediately before coronary angiography. Non-invasive markers of reperfusion determined just before coronary angiography were prospectively correlated to thrombolysis in myocardial infarction (TIMI) flow. Data analysis correlated these non-invasive indices with coronary flow (analysis A: TIMI 2-3 v TIMI 0-1 flow; analysis B: TIMI 3 v TIMI 0-2 flow). RESULTS: A sudden decrease in chest pain was the most common sign of reperfusion (36%), followed by reduction in ST segment elevation by >/= 50% (30%), and the development of a terminal negative T wave (20%) in the lead with the highest ST segment elevation. Reduction in ST segment elevation by > or = 50% and the appearance of an accelerated idioventricular rhythm (AIVR) had the highest positive predictive value for reperfusion. For analyses A and B, the positive predictive values were 85% and 66% for resolution of ST segment elevation, and 94% and 59% for AIVR, respectively. The presence of three or more non-invasive markers of reperfusion predicted TIMI 3 flow accurately in 80% of cases. CONCLUSIONS: The prospective use of non-invasive indices of reperfusion is simple, practical, and can be of value in assessing coronary patency in patients admitted with acute myocardial infarction. Using these indices, discrimination between TIMI 0-1 and TIMI 2-3 flow can be made with good accuracy. However, TIMI 3 flow cannot be determined reliably. The use of such non-invasive indices depends on the goal of reperfusion.

Ten-year experience with early angioplasty in 759 patients with acute myocardial infarction.

OBJECTIVES: How effective and safe is rescue percutaneous transluminal coronary angioplasty [PTCA] compared with primary PTCA, and is it cost effective? BACKGROUND: In acute myocardial infarction (AMI), primary PTCA has been shown to be beneficial in terms of clinical outcome. In contrast, the value of rescue PTCA has not been established. METHODS: In a retrospective analysis, we compared the angiographic and clinical outcomes of 317 consecutive patients who had rescue PTCA approximately 90 min after failed thrombolysis and 442 patients treated with primary PTCA. An estimation of interventional costs was compared with the strategies of primary and rescue PTCA or with the strategy of thrombolysis with rescue PTCA, when indicated. RESULTS: Baseline characteristics between primary and rescue PTCA were comparable for most variables. Treatment delay was longer for patients who had rescue PTCA: 240 min. versus 195 min. Coronary patency after PTCA was comparable: 90.2% for rescue PTCA and 91.4% for primary PTCA (p = 0.67, power 71.9%). In-hospital mortality rates were 4.7% and 6.6%, respectively (p = 0.37). Also, the other complications were fairly similar during the in-hospital phase and during one-year follow-up. Predictors of death were age, infarct size, localization of AMI, failed PTCA and left main stem occlusion. The estimated interventional costs during one-year follow-up were $7,377 for primary PTCA and $8,246 for rescue PTCA: difference $869 (11.7%). CONCLUSIONS: In this retrospective analysis of 759 patients with AMI, rescue angioplasty early after failed thrombolysis seems to be as effective and safe as primary PTCA. In the present evaluation, interventional costs of primary PTCA are less than those of rescue PTCA (p = 0.0001).

The incidence and consequences of mental disturbances in elderly patients post cardiac surgery--a comparison with younger patients.

BACKGROUND: Limited data exist about the incidence and consequences of mental confusion following open heart surgery in different age groups. Likewise, little is known about preoperative predictors of mental confusion. METHODS: Two-hundred consecutive patients, aged > or =75 years (Group 1), and 400 procedure- and gender-matched younger patients (Group 2) who underwent coronary or valvular surgery were included in a prospective study. The relation between postoperative mental confusion, mortality, morbidity, and quality of life was studied. RESULTS: Mental confusion was present in 11.8% Group 2 and 22.6% Group 1 patients. The incidence was higher after valvular surgery. Preoperative risk factors in Group 1 patients were diabetes mellitus, a history of heart failure, weak carotid pulsations, and repeat surgery. Late mortality, after a median follow-up duration of 31 months, was significantly worse in patients who were confused, which was related to the underlying disease. Recovery of quality of life was clearly diminished in elderly patients with confusion in contrast to younger patients. CONCLUSION: Postoperative mental confusion has a high incidence in the elderly population and is associated with a diminished quality of life.

Prospective randomised comparison between thrombolysis, rescue PTCA, and primary PTCA in patients with extensive myocardial infarction admitted to a hospital without PTCA facilities: a safety and feasibility study.

OBJECTIVE: To assess the safety and feasibility of acute transport followed by rescue percutaneous transluminal coronary angioplasty (PTCA) or primary PTCA in patients with acute myocardial infarction initially admitted to a hospital without PTCA facilities. DESIGN: In a multicentre randomised open trial, three regimens of treatment of acute large myocardial infarction were compared for patients admitted to hospitals without angioplasty facilities: thrombolytic treatment with alteplase (75 patients), alteplase followed by transfer to the PTCA centre and (if indicated) rescue PTCA (74 patients), or transfer for primary PTCA (75 patients). RESULTS: Between 1995 and 1997 224 patients were included. Baseline characteristics were distributed evenly. Transport to the PTCA centre was without severe complications in all patients. Mean (SD) delay from onset of symptoms to randomisation was 130 (75) minutes and from randomisation to angiography 90 (25) minutes. Death or recurrent infarction within 42 days occurred in 12 patients in the thrombolysis group, in 10 patients in the rescue PTCA group, and in six patients in the primary PTCA group. These differences were not significant. CONCLUSIONS: Acute transfer for rescue PTCA or primary PTCA in patients with extensive myocardial infarction is feasible and safe. Efficacy of rescue PTCA or primary PTCA in this setting will have to be tested in larger series before this approach can be implemented as "routine treatment" for patients with extensive myocardial infarction.

Value of the electrocardiogram in localizing the occlusion site in the left anterior descending coronary artery in acute anterior myocardial infarction.

OBJECTIVES: The study assessed the value of the electrocardiogram (ECG) as predictor of the left anterior descending coronary artery (LAD) occlusion site in relation to the first septal perforator (S1) and/or the first diagonal branch (D1) in patients with acute anterior myocardial infarction (AMI). BACKGROUND: In anterior AMI, determination of the exact site of LAD occlusion is important because the more proximal the occlusion the less favorable the prognosis. METHODS: One hundred patients with a first anterior AMI were included. The ECG showing the most pronounced ST-segment deviation before initiation of reperfusion therapy was evaluated and correlated with the exact LAD occlusion site as determined by coronary angiography. RESULTS: ST-elevation in lead aVR (ST elevation(aVR)), complete right bundle branch block, ST-depression in lead V5 (ST depression(V5)) and ST elevation(V1) > 2.5 mm strongly predicted LAD occlusion proximal to S1, whereas abnormal Q-waves in V4-6 were associated with occlusion distal to S1 (p = 0.000, p = 0.004, p = 0.009, p = 0.011 and p = 0.031 to 0.005, respectively). Abnormal Q-wave in lead aVL was associated with occlusion proximal to D1, whereas ST depression(aVL) was suggestive of occlusion distal to D1 (p = 0.002 and p = 0.022, respectively). For both the S1 and D1, inferior ST depression > or = 1.0 mm strongly predicted proximal LAD occlusion, whereas absence of inferior ST depression predicted distal occlusion (p < or = 0.002 and p < or = 0.020, respectively). CONCLUSIONS: In anterior AMI, the ECG is useful to predict the LAD occlusion site in relation to its major side branches.

Early referral for intentional rescue PTCA after initiation of thrombolytic therapy in patients admitted to a community hospital because of a large acute myocardial infarction.

BACKGROUND: If no in-house facilities for percutaneous transluminal coronary angioplasty (PTCA) are present, thrombolytic therapy is the treatment of choice for acute myocardial infarction (AMI). A few studies have shown benefit from rescue PTCA in patients directly admitted to centers with PTCA facilities. The obvious question arises whether patients with AMI initially admitted to a community hospital can benefit from early transfer for intentional rescue PTCA. METHODS AND RESULTS: One hundred sixty-five patients were transferred early for intentional rescue PTCA from a community hospital at a distance of 20 miles. On arrival at the angioplasty center, bedside markers were used to determine reperfusion. In case of obvious reperfusion, no invasive procedure was done; otherwise, coronary angiography and rescue PTCA, if necessary, was performed. During transfer, 1 (1%) patient died and 15 (9%) patients had arrhythmic or hemodynamic problems. Median time delay between onset of chest pain and arrival at the community hospital and the PTCA center was 61 minutes (range 0 to 413) and 150 minutes (range 28 to 472), respectively. In 66 (40%) patients, reperfusion was diagnosed by noninvasive reperfusion criteria on arrival at the PTCA center (group 1). Ninety-eight (59%) patients without evident noninvasive criteria of reperfusion underwent angiography 187 median minutes after the onset of chest pain. Forty-one (25%) patients had Thrombolysis In Myocardial Infarction grade 3 flow, and no further intervention was performed (group 2). In the remaining 57 (35%) patients, rescue PTCA was performed, which was successful in 96% (group 3). In-hospital mortality rate was lowest in group 1 compared with the other 2 groups (0% vs 7% vs 11%; P <.05). Reinfarction was highest in group 1 compared with the other groups (17% vs 5% vs 2%; P <.01). No significant differences were found in coronary artery bypass grafting, stroke, or bleeding complications. The 1-year follow-up data showed low revascularization rates; 2 (1%) patients died after discharge from the hospital. CONCLUSIONS: Early transfer of patients with large AMI for intentional rescue PTCA can be done with acceptable safety and is feasible within therapeutically acceptable time limits and results in additional early reperfusion in 33% of patients. A large, randomized, multicenter trial is needed to compare efficacy of intravenous thrombolytic treatment in a community hospital versus early referral for either rescue or primary PTCA.

The impact of the millennium problem on implantable pacemakers and defibrillators.

The unpredictable behavior of computer systems on January 1, 2000, known as the millennium problem or millennium 'bug,' also affects medical establishments and, due to the large use of computers in all kind of applications, cardiological clinics in particular. This review discusses the effect of the millennium computer problem on the implantation procedures and follow-up registries of implantable pacemakers and defibrillators. The review concludes that the transition in the next millennium will not influence the proper functioning of implanted pacemakers and defibrillators. The function of pacemaker/defibrillator programmers seems to be safe and no major difficulties are anticipated. Pacemaker databases and the logistics linked to the implantation and follow-up of patients and their pacemaker may and probably will be affected by the millennium transition. Using the FDA database on biomedical equipment, the actual status of all biomedical devices can be assessed.

Distal embolization during thrombectomy with use of the hydrolyser (hydrodynamic thrombectomy catheter): in vitro testing.

PURPOSE: To evaluate distal embolization while using the Hydrolyser (hydrodynamic thrombectomy catheter) with special attention to the severity of the stenosis and temporary distal or proximal flow obstruction. MATERIALS AND METHODS: The Hydrolyser procedure was assessed in plastic tubes (5-8 mm) with a 70% or 90% diameter stenosis with or without temporary distal flow obstruction and a 72-hour-old clot proximal to the stenosis. The weight of the embolized particles was established after passage through filters of 1,000, 500, 100, and 10 microm. To evaluate the influence of the absolute inner diameter of the stenosis 1.0-, 2.1-, and 3.0-mm stenoses were compared in 10-mm tubes. RESULTS: Thrombus removal was greater than 99.9% in all but one of the cases in the 5-8-mm tubes. Embolization with a weight of more than 1 mg was only found in tubes with a relative stenosis of 70% and a stenosis inner diameter of greater than 1.5 mm. There was a positive relationship between inner diameter of the stenosis and the amount of distal embolization. In the presence of a proximal or distal temporary flow obstruction during thrombectomy, no distal embolization greater than 1 mg was found. CONCLUSION: In this in vitro study, the Hydrolyser thrombectomy device demonstrated minimal distal embolization. The amount of distal embolization that did occur was related to the absolute stenosis diameter and could be prevented by a severe distal stenosis and/or a temporary proximal or distal flow obstruction.

Changing characteristics and in-hospital outcome in patients admitted with acute myocardial infarction. Observations from 1982 to 1994.

BACKGROUND: During the past decade, various new treatments have become available for patients with acute myocardial infarction. The effects of these treatment modalities have been studied extensively in selected patient groups. These studies indicate that early diagnosis, risk stratification and prompt initiation of treatment are of crucial importance for optimal benefit. However, it is not known whether prognosis changed in all patients admitted with an acute myocardial infarction. Also, the characteristics of the infarct population may have changed over time because of new medication regimens, invasive interventions and awareness of the importance of risk factors. METHODS: We studied all patients admitted with acute myocardial infarction in 1982, 1988 and 1994. Information on baseline characteristics, clinical variables and all interventions was collected. FINDINGS: In those 3 years 223, 227 and 235 patients were admitted because of an acute myocardial infarction. Patients admitted in 1994 were older, more often female and less often had a previous cardiac history. More patients admitted in that year had previous balloon angioplasty and coronary bypass grafting. Smoking habits decreased during the past decade. In-hospital mortality was 38 (17%) in 1982, 23 (10%) in 1988 and 22 (9%) in 1994 (P < 0.05). Variables related to high risk for in-hospital death in 1982 were higher age, low systolic blood pressure, atrial fibrillation, absence of accelerated idioventricular rhythm, sustained ventricular tachycardia and signs of left ventricular dysfunction; in 1988 the occurrence of non-sustained ventricular tachycardia, Killip class more than I, the absence of thrombolytic therapy, percutaneous transluminal coronary angioplasty or coronary artery bypass grafting were independently related to in-hospital death. In 1994, high risk variables for in-hospital death were dyspnoea on admission, sustained ventricular tachycardia, female gender, higher creatinine on admission, and a previous cardiac history. INTERPRETATION: In-hospital mortality for unselected patients admitted with an acute myocardial infarction decreased between 1982 and 1988 and remained the same between 1988 and 1994, in spite of further ageing of the population. In the study period there has been a change in baseline characteristics and high risk variables for in-hospital death after myocardial infarction.

Comparison of arterial wall reaction after passage of the Hydrolyser device versus a thrombectomy balloon in an animal model.

PURPOSE: This study was designed to compare the reaction of the vessel wall after application of the Hydrolyser hydrodynamic thrombectomy device to the reaction after use of a balloon thrombectomy catheter. The influence of the vessel inner diameter on vessel wall reaction was evaluated after passage of the Hydrolyser. MATERIALS AND METHODS: After measurement of the vessel inner diameter with intravascular ultrasound (US), 102 segments of femoral and carotid arteries of goats were treated with one of the following four procedures: passage of the intravascular US catheter alone; passage of the Hydrolyser without or with an activated jet; or passage of an inflated thrombectomy balloon. Histologic evaluation was performed after 3 weeks. RESULTS: Intimal thickening (more than five cell layers of neointima) 3 weeks after treatment occurred more frequently after passage of the balloon than after any of the other procedures (P < .001). For vessels with a diameter of 3-4 mm, 4-5mm, or more than 5 mm, no significant difference in vessel wall reaction was observed following Hydrolyser passage. CONCLUSION: In this model, passage of the Hydrolyser device resulted in less intimal reaction compared with the thrombectomy balloon.

Changes in wall motion in patients treated for unstable angina. A suggestion of the stunned and hibernating myocardium in humans. UNASEM Collaborative Study Group. Unstable Angina Study Using Eminase.

BACKGROUND: A double-blind, placebo-controlled study using anistreplase was performed in 159 patients with unstable angina. All patients had a history of unstable angina combined with typical ECG changes and without evidence of a previous, recent, or ongoing myocardial infarction. The purpose of the present study was to analyze the relationship between the patency of the culprit artery and the behavior of the ischemia-related regional left ventricular (LV) wall motion. METHODS AND RESULTS: On entry to the study, all patients received conventional drug therapy: i.v. nitroglycerin therapy, an oral beta-blocking agent, and a calcium antagonist. Baseline angiography was carried out within 3 h after randomization, a mean of 4.2 +/- 3.0 h (range, 1 to 17 h) after the last attack of chest pain. Treatment with trial medication was withheld in 33 cases. Sixty-five patients with coronary artery disease received anistreplase (30 U/5 min)/heparin and 61 patients heparin-only therapy. Angiography was repeated 20.6 +/- 4.6 h (mean +/- SD; range, 12 to 39 h) after the baseline angiographic study. To assess changes in regional myocardial wall motion, the LV wall was divided into seven segments. The ischemia-related coronary artery stenosis was calculated quantitatively and related to the quantitatively assessed mean regional left ventricular ejection fraction (RLVEF) of the ischemia-related segments. In 118 of 126 patients who received trial medication, we found that anistreplase/heparin therapy leads to a significantly (p < 0.01) greater reduction in coronary artery diameter stenosis than heparin-only therapy (n = 63, mean +/- SD, 11 +/- 22, vs n = 55, mean +/- SD, 3 +/- 11%). Anistreplase/heparin therapy was related to a larger significant improvement of the ischemia-related RLVEF than heparin-only therapy, although the latter association was not statistically significant (n = 63, mean +/- SD, 7 +/- 15, vs n = 55, mean +/- SD, 5 +/- 14%). The effects of change of coronary artery stenosis on regional LV wall motion were also determined. A paradoxical finding was that a persistently occluded vessel or a vessel showing an increase in coronary artery stenosis was associated with a greater improvement of the ischemia-related RLVEF than a reopened vessel or a vessel with a reduction in coronary artery stenosis (n = 15, mean +/- SD, 7 +/- 11, vs n = 41, mean +/- SD, 8 +/- 13, vs n = 15, mean +/- SD, 1 +/- 12, vs n = 47, mean +/- SD, 5 +/- 16%, NS). One day after the last attack of chest pain, the regional LV wall motion was still abnormal in about 20% of patients. CONCLUSION: In these patients with unstable angina, the LV wall motion improved both in the treated and the control group at follow-up angiography 1 day later. Improved coronary arterial anatomy was associated with a lesser improvement of the LV contractile function than when worsening of the coronary angiographic appearance occurred. There is no rational explanation of these results. This is a beginning of an effort to elucidate the clinical significance of the stunned and hibernating myocardium in humans.

Evaluation of new self-learning techniques for the generation of criteria for differentiation of wide-QRS tachycardia in supraventricular tachycardia and ventricular tachycardia.

This study presents a comparison of three different methods for differentiating between supraventricular and ventricular tachycardias with wide-QRS complex. One set of criteria, derived using classical statistical techniques, was compared with two new self-learning computer techniques: the artificial neural networks and the induction algorithm approach. By analyzing the results obtained in an independent test set, using these new techniques, the criteria defined by the classical method could be improved.

Effects of acute volume changes on P wave characteristics: correlation with echocardiographic findings in healthy men.

INTRODUCTION: This study was performed to determine the effect on the P wave of different hemodynamic loads to the heart. METHODS AND RESULTS: Signal-averaged P wave ECG and atrial echocardiographic measurements were obtained from eight healthy male volunteers at rest and after infusion of 1000 mL of plasma expander (Haemaccel) over 15 minutes. These measurements were repeated 24 hours later at rest and after 0.8 mg of nitroglycerin given sublingually. The effect of positional changes was also studied. At rest the amplitude of the P wave and the time of the maximal the P wave amplitude were reproducible. Sitting increased heart rate variability; no significant changes of the P wave were found. Volume overload decreased the heart rate and increased the atrial size on echocardiography with changes in lead V1 (earlier appearance of the first positive deflection). Nitroglycerin administration increased heart rate and decreased the echocardiographic size of the atria, the latter not reaching statistical significance. Administration of nitroglycerin induced P wave amplitude rise in leads I and II. The maximal power in fast Fourier transformation for calculated orthogonal leads X and Y increased as well. CONCLUSIONS: Amplitude behavior in leads I, II, and V1 appears to correlate with load conditions, particularly with volume redistribution. In healthy men subtle changes in the P wave morphology after volume changes can be detected by the signal-averaged ECG. Application of these findings in patients following acute changes in circulation needs further investigation.