Altered maternal left ventricular contractility and function during normal pregnancy.

OBJECTIVES: To evaluate maternal left ventricular (LV) systolic and diastolic function during normal pregnancy by non-invasive measures of LV contractility incorporating loading conditions. METHODS: Sixty-five women were examined using echocardiography, including tissue Doppler and two-dimensional speckle tracking, and subclavian artery pulse trace recordings at gestational weeks 14-16, 22-24 and 36, and at 6 months postpartum. RESULTS: The mean ± SD age of the women was 32.0 ± 4.6 years. Cardiac output and LV end-diastolic volume were on average 20% and 23% higher, respectively, during pregnancy, compared to that at 6 months postpartum (both, P < 0.01). LV ejection fraction, global peak systolic strain and rate-corrected LV velocity of circumferential fiber shortening (Vcfc) were 11%, 6% and 6% lower, respectively, at 36 weeks' gestation compared to at 6 months postpartum (all, P < 0.01). Afterload, measured as LV end-systolic wall stress (ESWS) increased by 10% between 14-16 and 36 weeks' gestation (P < 0.01). Analysis of the relationship between Vcfc and ESWS revealed that LV contractility was lower during pregnancy than at 6 months postpartum. Changes in diastolic function were demonstrated by 11% lower mitral early diastolic (E) wave velocity, 8% lower tissue Doppler early diastolic velocity (e') and 13% higher left atrial area (all P < 0.01) during pregnancy. Tissue Doppler E/e' remained unaltered (P = 0.78). CONCLUSIONS: During normal pregnancy, LV contractility is lower than it is at 6 months postpartum. This is associated with increased LV and left atrial area, whereas filling pressures are unchanged. These findings suggest that pregnancy exerts a larger load on the cardiovascular system than previously assumed.

Therapeutic hypothermia after out-of-hospital cardiac arrest: experiences with patients treated with percutaneous coronary intervention and cardiogenic shock.

BACKGROUND: Therapeutic hypothermia has been shown to increase survival after out-of-hospital cardiac arrest (OHCA). The trials documenting such benefit excluded patients with cardiogenic shock and only a few patients were treated with percutaneous coronary intervention prior to admission to an intensive care unit (ICU). We use therapeutic hypothermia whenever cardiac arrest patients do not wake up immediately after return of spontaneous circulation. METHODS: This paper reports the outcome of 50 OHCA patients with ventricular fibrillation admitted to a tertiary referral hospital for immediate coronary angiography and percutaneous coronary intervention when indicated. Patients were treated with intra-aortic balloon counterpulsation (IABP) (23 of 50 patients) if indicated. All patients who were still comatose were treated with therapeutic hypothermia at 32-34 degrees C for 24 h before rewarming. The end-points were survival and cerebral performance category (CPC: 1, best; 5, dead) after 6 months. RESULTS: Forty-one patients (82%) survived until 6 months. Thirty-four patients (68%) were in CPC 1 or 2, and seven (14%) were in CPC 3. Of the 23 patients treated with IABP, 14 (61%) survived with CPC 1 or 2. In patients not treated with IABP, 20 patients (74%) survived with CPC 1 or 2. Forty patients (80%) developed myocardial infarction. Percutaneous coronary intervention was performed in 36 patients (72%). CONCLUSION: In OHCA survivors who reached our hospital, the survival rate was high and the neurological outcome acceptable. Our results indicate that the use of therapeutic hypothermia is justified even in haemodynamically unstable patients and those treated with percutaneous coronary intervention.

The effect of a neuropeptide Y Y1 receptor antagonist in patients with angina pectoris.

AIMS: Neuropeptide Y (NPY) is a potent vasoconstrictor released during sympathetic activation that may be involved in myocardial ischaemia. We examined the effect of a Y1 receptor antagonist on haemodynamic and ischaemic responses to exercise in patients with coronary artery disease. METHODS AND RESULTS: Eighty-two evaluable male patients were included in a randomized, double blind, two-way crossover study with a low dose (6.7 microg/kg/min; n=59)and a high dose (13.3 microg/kg/min; n=23) of the Y1 receptor antagonist AR-H040922 given as infusions for 2h or placebo. Myocardial ischaemia during a symptom-limited exercise test was monitored by conventional ST-segment analysis and heart rate (HR)-adjusted ST changes including the ST/HR slope and ST/HR recovery. Administration of the high dose AR-H040922 attenuated systolic blood pressure by 6-11 mmHg (p<0.05) during and after exercise without affecting HR. None of the two doses of AR-H040922 influenced any of the ischaemic parameters or duration of exercise, however. The maximal increase in NPY was higher during AR-H040922 (p<0.05) compared with placebo. CONCLUSIONS: Selective NPY Y1 receptor blockade attenuates the increase in blood pressure during exercise indicating a role for endogenous NPY in blood pressure regulation. Despite this effect, the Y1 receptor antagonist did not influence exercise-induced ischaemic parameters in patients with coronary artery disease.

Cardiac enzymes after transmyocardial laser treatment with CO2 laser.

OBJECTIVES: The aim of the present study was to examine postoperative serum levels of cardiac enzymes after transmyocardial laser treatment (TML) and to evaluate any associations between this release, postoperative cardiac events and change in ejection fraction after 3 months' follow-up. DESIGN: Forty-nine patients with angina pectoris Canadian Cardiovascular Society Angina Score Class III & IV refractory to medical therapy and untreatable by coronary artery bypass or percutaneous transluminal angioplasty treated with CO2 laser were included. Inclusion criteria were age less than 75 years, left ventricular ejection fraction greater than or equal to 30% and myocardial regions with reversible ischemia. Serum levels of aspartate aminotranspherase (ASAT), alanine aminotranspherase (ALAT) and MB-isoenzymes of creatine kinase (CK-MB) were followed during the first 72 h after surgery. Ejection fractions were estimated by multiple-gated acquisition ventriculography at inclusion and 3 months postoperatively. RESULTS: A significant increase in serum markers of myocardial necrosis was observed 8 h after surgery. A subsequent increase from 8 to 24 h after surgery was associated with the presence of postoperative cardiac adverse events. An inverse correlation was found between peak level of cardiac enzymes and change in ejection fraction from baseline to 3 months' follow-up. CONCLUSIONS: TML with CO2 laser is followed by a significant increase in serum levels of cardiac enzymes after 8 h. Further significant increases are associated with cardiac adverse events postoperatively. Peak enzyme values are inversely correlated with change in ejection fraction from baseline to 3 months' follow-up.

Effects of transmyocardial revascularization on myocardial perfusion and systolic function assessed by nuclear and magnetic resonance imaging methods.

OBJECTIVE: There is no obvious explanation, except placebo, to the symptomatic effect of transmyocardial laser revascularization (TMR) in patients with refractory angina. Whether TMR improves myocardial perfusion or relieves symptoms without altering cardiac function is not clarified. METHODS: One hundred patients with refractory angina were randomized 1:1 to TMR (CO2 laser) and medical treatment, or medical treatment alone. Technetium 99m (99mTc)-tetrofosmin myocardial perfusion tomography (SPECT), quantitative myocardial perfusion gated SPECT (QGSPECT), technetium 99m (99mTc) multiple gated acquisition radionuclide ventriculografi (MUGA) and cine-magnetic resonance imaging (cine-MRI) were performed at baseline and after 3 and 12 months. RESULTS: Following TMR, a slight reduction in left ventricular ejection fraction (LVEF) (p < 0.05) was observed (MUGA and QGSPECT) compared to baseline. Inclusion of incomplete studies (QGSPECT) revealed a significant reduction in LVEF and increase in left ventricular end-diastolic volume (LVEDV) (p < 0.05) compared to a control group. Otherwise, no between-group comparisons showed statistically significant differences. CONCLUSION: TMR did not improve myocardial perfusion, but led to a reduction in LVEF and increase in LVEDV, however not significantly different from the control group.

Myocardial performance after transmyocardial revascularization with CO(2)laser. A dobutamine stress echocardiographic study.

AIMS: Transmyocardial laser revascularization is a treatment for patients with severe angina pectoris not eligible for conventional revascularization. The effects on myocardial function and reversible ischaemia have not been clarified. METHODS AND RESULTS: One hundred patients with refractory angina not eligible for conventional revascularization were randomized 1:1 to receive continued optimal medical treatment or transmyocardial revascularization with CO(2)laser in addition to medical treatment. Dobutamine stress echocardiography examinations were performed at baseline and at 3 and 12 months after randomization. The effects of transmyocardial revascularization on myocardial function and reversible ischaemia were assessed by visual interpretation of cineloops at rest and during stress in a 16-segment model. After transmyocardial revascularization resting left ventricular wall motion abnormalities increased (P<0.01), whereas wall motion during dobutamine stimulation remained unchanged. The number of probably non-viable segments increased (P<0.01) with a corresponding decrease in the number of ischaemic segments. Fewer patients had the dobutamine infusion discontinued because of chest pain after transmyocardial revascularization with laser, but the chest pain threshold did not increase significantly. CONCLUSION: Following transmyocardial revascularization, resting wall motion abnormalities worsened, wall motion abnormalities during dobutamine stimulation remained unchanged and the number of probably non-viable segments increased.

Perioperative cardiac function and predictors for adverse events after transmyocardial laser treatment.

BACKGROUND: Previous studies have reported that mortality and morbidity after transmyocardial laser treatment (TML) mainly occur perioperatively. The present study was designed to evaluate left-ventricular function and identify risk factors for cardiac-related adverse events in this phase. METHODS: Forty-nine patients were studied. The inclusion criteria were angina pectoris Canadian Cardiovascular Society Angina Score (CCSAS) class III and IV refractory to medical therapy and untreatable by coronary artery bypass graft or percutaneous transluminal coronary angioplasty, age less than 75 years, left ventricular ejection fraction greater than or equal to 30%, and myocardial regions with reversible ischemia. Hemodynamic data and cardiac adverse events were registered. The follow-up time was 30 days. RESULTS: A transient decrease in mean cardiac index (CI) was observed, reaching its minimum immediately after end of the surgical procedure (1.8+/-0.4, p<0.01 vs. baseline). Two patients (4%) died during the postoperative period (30 days). Seventeen patients (35%) experienced adverse cardiac-related events, where CCSAS class IV, unprotected left main stem stenosis, and diabetes mellitus were identified as risk factors in a multivariate analysis. CONCLUSIONS: A transient impairment of left ventricular function was observed after TML. The morbidity and mortality after TML were almost exclusively cardiac-related, identifying CCSAS class IV, unprotected left main stem stenosis, and diabetes as risk factors.

Transmyocardial revascularization with CO2 laser in patients with refractory angina pectoris. Clinical results from the Norwegian randomized trial.

OBJECTIVES: The purpose of the study was to evaluate clinical effects, exercise performance and effect on maximal oxygen consumption (MVO2) of transmyocardial revascularization with CO2-laser (TMR) in patients with refractory angina pectoris. BACKGROUND: Transmyocardial laser revascularization is a new method to treat patients with refractory angina pectoris not eligible for conventional revascularization. Few randomized studies comparing TMR with conventional treatment have been published. METHODS: One hundred patients with refractory angina not eligible for conventional revascularization were block-randomized in a 1:1 ratio to receive continued optimal medical treatment (MT) or TMR in addition to MT. The patients were evaluated at baseline and at three and 12 months with end points to symptoms, exercise capacity and MVO2. RESULTS: Transmyocardial laser revascularization resulted in significant relief in angina symptoms after three and 12 months compared to baseline. Time to chest pain during exercise increased from baseline by 78 s after three months (p = NS) and 66 s (p < 0.01) after 12 months in the TMR group, whereas total exercise time and MVO2 were unchanged. No significant changes were observed in the MT group. Perioperative mortality was 4%. One year mortality was 12% in the TMR group and 8% in the MT group (p = NS.) CONCLUSIONS: Transmyocardial laser revascularization was performed with low perioperative mortality and caused significant symptomatic improvement, but no improvement in exercise capacity.

[Transmyocardial laser treatment--a new treatment modality in pronounced angina pectoris?]. / Transmyokardial laserbehandling--et nytt tilbud ved uttalt angina pectoris?

Transmyocardial laser treatment is currently being evaluated as a treatment modality for patients with severe coronary artery disease unsuitable for conventional revascularization with percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. The original hypothesis was that laser-made channels could contribute to myocardial perfusion by conducting blood from the left ventricular cavity into the ischemic myocardium. Results from clinical trials suggest that transmyocardial laser treatment leads to a significant decrease in physician-assessed angina scores and improvement of quality of life. There are, however, conflicting data regarding the effect of myocardial perfusion, and the mechanisms responsible for the observed clinical effect remain unclear. It has been suggested that the angina relief is caused by destruction of myocardial peripheral nerve-endings and improved perfusion through induction of angiogenesis and collateral recruitment. A review of transmyocardial laser treatment with emphasis on experimental and clinical results, based on a thoroughly performed search on Medline of English language publications up until May 1999, is presented.

[Stress echocardiography with dobutamine. A new method for diagnosis of ischemia]. / Stressekkokardiografi med dobutamin. En ny metode for iskemidiagnostikk.

Dobutamine stress echocardiography was performed in 24 patients with angiographically defined coronary artery stenosis, before they underwent percutaneous transluminal coronary angioplasty. Ischemia was detected on stress-ECG in 13 patients. In 19 patients ischemia could be detected with dobutamine stress echocardiography. The method was highly sensitive for detecting ischemia in patients with two vessel or three vessel disease and in patients with affection of only the left anterior descending artery. In patients with one vessel disease the method showed low sensitivity. The most common side effects of dobutamine infusion were flushing and palpitations. One patient suffered atrial fibrillation and one patient had a short and self-limiting ventricular tachycardia. The method seems to be a useful and safe supplementary tool for detecting myocardial ischemia. It is also useful for characterizing the physiological effect of coronary artery stenosis.