[Results of percutaneous coronary interventions in Iceland during 1987-1998.].

PURPOSE: To evaluate potential changes in clinical indications and the composition of the patient population undergoing percutaneous coronary intervention (PCI) in Iceland from 1987 to 1998. Furthermore, to assess changes in success rate and major complications for the procedure during the study interval in a small nation with one PCI centre. MATERIAL AND METHODS: The first PCI was performed in Iceland in May 1987. A registry has been kept from the start that includes clinical and procedural data, and records of complications and mortality. During the study interval a total of 2440 PCIs were performed. The annual procedure rate was low at first, with a steep rise during the last years. Based on procedural changes over the years the study interval was divided into three periods: I. 1987-1992 (471 procedures); the learning years, II. 1993-1995 (796 procedures); increasing number of PCIs and the method established, III. 1996-1998 (1173 procedures); increasing use of stents and new antiplatelet regime used. RESULTS: From period I to III, the rate of elective PCI declined from 82% to 52% (p<0.001), subacute procedures increased from 14% to 44% (p<0.001), acute PCI from 0.8% to 3% (p<0.05), and ad hoc procedures from 0.4% to 28% (p<0.001). This reflects an increase in PCI on patients with acute coronary syndromes, as the ratio of patiens with unstable angina increased from 15% to 36% (p<0.001). Also, 1-vessel PCI decreased proportionally from 93% to 83%, while 2 and 3 vessel procedures increased from 7% to 17% (p<0.001). The proportion of patients 70 years or older increased from 7% to 27% (p<0.001). Still, the success rate for PCI increased from 83% to 93% (p<0.001) and the use of stents rose sharply from 0% to 56%. The ratio of PCI due to restenosis declined somewhat between period II and III, from 15% to 12% (p=0.06). Simultaneously, the rate of acute coronary bypass surgery after PCI decreased from 4.2% to 0.2% (p<0.001) and significantly fewer patients had elevated creatinine kinase levels (4.0% vs 2.7%, respectively, p<0.05). However, clinical acute myocardial infarction after PCI remained similar at 1.3% and 0.9%, and the in hospital mortality was 0.6% and 0.4%. CONCLUSIONS: On a national basis the rate of PCI in Iceland is amongst the highest in Europe. Thus, in 1998, when the population in Iceland was 275,000, 453 PCIs were done (1647 procedures per million inhabitants). An increased number of subacute and acute PCIs is carried out, more complicated procedures are performed in patients with widespread disease, and the patient population is growing older. Still, the success rate is high and the frequency of complications and mortality relatively low.

Activated and total coagulation factor VII, and fibrinogen in coronary artery disease.

Fibrinogen (FBG) and total coagulation factor VII (FVIIc) concentrations are higher in those patients with coronary artery disease who are at increased future risk of acute ischemic events. The relationship between activated factor VII (FVIIa) and cardiovascular events, however, has not been intensively studied. Data were collected from 401 consecutive patients who underwent coronary angiography because of suspected coronary artery disease. Conventional risk factors FVIIc, FVIIa and FBG were assessed in relation to the severity of coronary artery disease, left ventricular ejection fraction, and previous clinical events. A strong positive correlation was found between FVIIa and FVIIc (p < 0.001), but neither FVIIa nor FVIIc correlated with FBG. No correlation was found between FVIIa, FVIIc or FBG levels and stenosis score for the severity of coronary artery disease, and all were similar in patients with stable or unstable angina pectoris. Multivariate regression analysis showed FVIIc to be higher in women (p = 0.004), and positively related to triglycerides (p = 0.001) and HDL cholesterol (p = 0.006), but not to a previous myocardial infarction or total cholesterol. FVIIa, on the other hand, was lower in patients with a previous myocardial infarction (p = 0.004), higher in women (p = 0.001) and those that previously had undergone percutaneous transluminal coronary angioplasty (p = 0.039), and positively related to total cholesterol (p = 0.011), duration of coronary artery disease (p = 0.032), and smoking (p = 0.008). FBG was positively associated with a previous myocardial infarction (p = 0.013), hypertension (p = 0.016), smoking (p = 0.005), and the thrombocyte count (p < 0.001). Finally, stepwise logistic regression analysis verified a previous myocardial infarction to be negatively associated with FVIIa (p = 0.03), and positively with FBG (p = 0.03), total cholesterol (p = 0.02), and the severity of coronary artery disease (p < 0.001). In conclusion, in patients suspected of coronary artery disease undergoing cardiac catheterization, FVIIa was decreased and FBG increased in those who had a previous myocardial infarction. FVIIa, FVIIc, or FBG levels were not, however, related to the severity of coronary artery disease, and they were similar in patients with stable or unstable angina pectoris.

Cardiovascular and electrocardiographic effects of iopentol in left ventricular angiography. Comparison of the low-osmolar, non-ionic iopentol (Imagopaque 350) and the hyper-osmolar, ionic metrizoate meglumine-Na-Ca (Isopaque Coronar 370) in patients with coronary heart disease.

UNLABELLED: The aim of the study was to evaluate and compare the hemodynamic and electrocardiographic effects following injection of the non-ionic, low-osmolar contrast medium iopentol (Imagopaque 350, Nycomed Imaging AS, Oslo, Norway) and the ionic, hyper-osmolar contrast medium metrizoate meglumine-Na-Ca (Isopaque Coronar 370, Nycomed Imaging AS, Oslo, Norway) when used for left ventricular angiography. The study was performed in a double-blind, randomized manner in 82 patients with severe coronary heart disease. The patients who received iopentol experienced less adverse events and subjective discomfort of lesser intensity than those who received metrizoate (p = 0.0001). Both contrast media induced a biphasic change in left ventricular (LV) systolic pressure, with an initial fall followed by a prolonged rise, but the alterations were statistically significantly more pronounced with metrizoate than with iopentol. The changes in LV end-diastolic pressure (p = 0.023), and LV negative dP/dt (p = 0.002) were significantly more pronounced with metrizoate than with iopentol. Cardiac output and heart rate increased more with metrizoate, while stroke volume was equally increased by both agents. A prolonged increase in the QT-interval, throughout the 10-min observation period, was seen only after injection of metrizoate (p = 0.0006 for comparison between contrast media). CONCLUSION: Iopentol was well tolerated and induced markedly less severe hemodynamic and electrocardiographic alterations than did metrizoate in patients with severe coronary heart disease.

[Newly acquired right bundle branch block. Association with heart disease and risk factors in the Reykjavik Study.].

PURPOSE: To find risk factors for the appearance of right bundle branch block (RBBB) and to assess the prognosis of people with it. METHODS: Subjects were participants in the Reykjavik Study who had acquired RBBB following an examination in a previous stage in this prospective population study, carried out in five stages in 1967-1991. Cases with two matched controls were recruited for a special examination in 1992. RESULTS: Acquired RBBB was seen in 33 men and 14 women. Multivariate analysis showed, compared to the total population, that men with RBBB more often had cardiomegaly (odds ratio=OR 1.7;confidence limit=CL 1.2-2.5) women more often took antihypertensive drugs (OR 2.5; CL 1.5-4.1) and had lower diastolic blood pressure (OR 0.97; CL 0.95-0.99). Predictive factors in people with acquired RBBB were age (men: relative risk=RR 1.08; CL 1.05-1.11, women: RR 1.09; CL 1.02-1.17) and antihypertensive medication in women (RR 3.5; CL 1.2-10.4). There was no significant difference between cases and controls regarding examination, echocardiography and mortality. CONCLUSION: Factors associated with the appearance of RBBB are mainly age, cardiomegaly and antihypertensive medication.

Factors predicting maintenance of sinus rhythm after direct current cardioversion of atrial fibrillation and flutter: a reanalysis with recently acquired data.

A prospective study was conducted to evaluate how many patients maintain normal sinus rhythm after direct current (DC) cardioversion of atrial arrhythmias and to assess factors predictive of long-term success. The study group consisted of 61 patients (45 men) aged 18-88 years (mean age 66 +/- 11 years) who underwent cardioversion at our department from October 1990 to June 1992. Prior to cardioversion, the patients' medical history, medications, heart size on chest X ray, and echocardiographic findings were reviewed. Overall, 41 (67.2%) patients were in atrial fibrillation, while 20 (32.8%) had atrial flutter. Only 15% of the patients had valvular heart disease. Sinus rhythm was restored by DC cardioversion in 47 (77%) patients, none of whom experienced an embolic event prior to discharge. Patients with atrial flutter had a higher conversion rate (95%) than those in atrial fibrillation (68.3%; p = 0.024), and also patients with an arrhythmia for less than 1 week (94.4%) compared to those with a longer or unknown duration (69.8%; p = 0.047). The primary success rate was not influenced by heart size on chest X ray or echocardiographic variables. The study protocol aimed at following up the patients for 1 year after cardioversion. Of the 47 patients who converted to sinus rhythm data are available on 44 for a mean follow-up of 11 +/- 3 months (range 1-14 months), at which time 25 (57%) still remained in sinus rhythm. Heart size on the chest X ray was significantly increased in the group that did not maintain sinus rhythm (p = 0.03) and their left atrial size on echocardiography was slightly increased (p = 0.10). Patients who originally had atrial flutter were more likely to remain in sinus rhythm than those who had been in atrial fibrillation (p = 0.12), as did patients with an arrhythmia for less than 1 week prior to cardioversion in comparison to those with a longer or unknown duration (p = 0.11). Thus, in contrast to previous reports, according to these recent data on a patient population with a low prevalence of valvular heart disease, DC cardioversion can be attempted in most patients with atrial tachyarrhythmias. Clinical factors, heart size on chest X ray and echocardiographic findings should, however, be considered before deciding to perform DC cardioversion.

Predominance of aortic calcification as an atherosclerotic manifestation in women: the Reykjavik study.

Since 1967 the Reykjavík study has monitored coronary artery disease and its risk factors in randomly selected cohorts. From 1979 to 1984, 3246 men and 3545 women aged 45-74 years were studied. Routine biplane chest X rays were assessed by a radiologist who noted the presence or absence of aortic calcification (AC), but had no detailed knowledge of the subjects. Overall, AC was diagnosed in 283 (8%) women, but in only 54 of the men (1.7%). In the women, the prevalence of AC increased from 2.0% at age 45-49 years to 17.1% at the age of 70-74 years, while in men it was 0 and 8.3%, respectively. In women, multivariate analysis of risk factors showed AC to be positively related to systolic and negatively related to diastolic blood pressure, indicating a potential relation to pulse pressure. Furthermore, AC was independently associated with age, drug treatment for hypertension, nonfasting blood sugar, use of antidiabetic drugs, total serum cholesterol levels, and the amount of smoking. Too few men had AC for multivariate assessment of risk factors. In addition, in women AC was also related to a previous myocardial infarction (p < 0.05), mortality from coronary artery disease (p < 0.01), and the presence of intermittent claudication (p < 0.01). In men, however, AC was related only to total mortality (p < 0.05). Thus, these data show AC to be more prevalent in women, independently associated with recognized atherosclerotic risk factors, and a potential marker for coronary and peripheral artery disease.

Left ventricular myocardial perfusion and function in systemic sclerosis before and after diltiazem treatment.

To examine left ventricular (LV) myocardial perfusion and function, in systemic sclerosis. Myocardial perfusion was assessed at rest, during cold exposure, and at peak exercise in 10 patients with systemic sclerosis. Seven of the 10 patients were examined with Doppler echocardiography; before and after long-term diltiazem treatment. Compared with average resting values, isotope uptake was increased by 48% after exercise, compared with cold exposure the exercise value was increased by 35%. After 11 months of diltiazem treatment there was no change in myocardial uptake, compared with respective values before treatment. Doppler echocardiography showed an increase in LV end-diastolic diameter, fractional shortening, and left ventricular outflow tract velocity, after treatment. This indicates that long-term diltiazem treatment does not increase myocardial perfusion at rest, post-exercise, or during cold exposure. On the other hand diltiazem treatment may improve left ventricular performance.

A comparison of different coding formats for digital coding of video using MPEG-2.

This correspondence addresses the problem of maximizing the subjective picture quality at given bit rates for coded video. Coding is carried out using different picture formats. The parameters involved are the number of pixels horizontally and vertically and interlacing/noninterlacing. The coding is done according to the MPEG-2 standard.

[Marfan's syndrome in Iceland.].

Marfan's syndrome is a heritable collagen disorder manifested by defects in the ocular, skeletal and cardiovascular systems. It is inherited as an autosomal dominant trait. The objectives of this study were to study the prevalence and clinical presentation of Marfan's syndrome in Iceland. We assessed the records of patients diagnosed with Marfan's syndrome during the years 1989-94 at all the major hospitals in Iceland. Hospital cardiologists, pediatricians and ophthalmologists gave valuable information, as did some general practitioners. All patients who agreed to participate were evaluated by an ophthalmologic inspection and an echocardiogram was obtained. A family history was taken and a general physical examination was performed. Twenty two patients were evaluated, at the age seven to 71 years. Seventeen of them had a definitive diagnosis of Marfan's syndrome with a mean age of 27 years. Five patients did not meet the clinical criteria for Marfan's syndrome. Accordingly the prevalence of Marfan's syndrome in Iceland is 6.5/100.000. Ocular involvement was observed in 14 (82%) and 11 (65%) had a dislocated lens. Cardiovascular abnormalities were seen in 11 (65%) patients, nine (53%) had aortic root dilatation and six (35%) had mitral valve prolaps. All patients had skeletal abnormalities. They were tall, skinny, with long extremeties and arachnodactyly. Pectus carinatum was observed in seven (41%) patients. A family history was noted in 12 patients and five (29%) seem to be sporadic cases. Thus, Marfan's syndrome exists in Iceland and it's prevalence and clinical presentation seems to be in concordance with other published studies in the western world.

[Factors predicting long-term success of DC cardioversion of atrial arrhythmias.].

A prospective study was conducted to evaluate how many patients maintain sinus rhythm after DC cardioversion of atrial arrhythmias and to assess factors predictive of long-term success. The study group consisted of 61 patients (45 men, 16 women) aged 18-88 years (mean age 66 +/- 11 years) who undervent cardioversion, at the Department of Cardiology, Landspitalinn, from October 1990 to June 1992. Prior to cardioversion data were collected on the patient's medical history, medications, heart size on chest X-ray, and echocardiographic findings. Overall, 41 (67.2%) patients were in atrial fibrillation while 20 (32.8%) had atrial flutter. Sinus rhythm was restored by DC cardioversion in 47 (77%) patients, none of whom experienced an embolic event prior to discharge. Patients with atrial flutter had a higher conversion rate (95%) than those in atrial fibrillation (68.3%) (p=0.024) and also those who had had an atrial arrhythmia for less than one week (94.4%) in comparison to patients with an arrhythmia of longer or unknown duration (69.8%) (p-0.047). The primary success rate was not influenced by heart size on chest X-ray or echocardiographic variables. The study aimed to follow the patients for one year after cardioversion. Of the 47 patients who converted to sinus rhythm data are available on 44 for a mean follow-up of 11 +/- 3 months (range 1-14 months), at which time 25 (57%) still remained in sinus rhythm. Heart size on chest X-ray was significantly increased in the group that did not maintain sinus rhythm (p=0.03), and their left atrial size on echocardiography was slightly increased (p=0.10). Patients who originally had atrial flutter were more likely to remain in sinus rhythm than those who had been in atrial fibrillation (p=0.12), as did those who had had the arrhythmia for less than one week prior to cardioversion compared to those who had a longer or unknown duration (p=0.11). We conclude, that DC cardioversion can be attempted in most patients with atrial flutter or fibrillation. However, clinical factors, heart size on chest X-ray and echocardiographic findings should be considered before deciding to perform DC cardioversion.

[Autonomic nervous dysfunction in insulin-dependent (type 1) diabetic men.].

The development of autonomic nervous dysfunction (AND) in subjects with diabetes influences life expectancy and may cause sudden death. The present study evaluates disturbances of AND in 41 men with type 1 diabetes mellitus, but without heart symptoms, and the relationship with other long term diabetic complications and blood sugar control. Their age ranged 18-50 years (mean 34 +/-8 years) and the duration of diabetes 1-43 years (mean 13 +/-10 years). A control group consisted of 18 healthy men of similar age. Heart rate and blood pressure responses during standard autonomic tests were assessed by a computer program, vibration sensibility by a Biothesiometer, and an exercise test was performed. AND was more frequent in diabetics than controls (39% versus 6%, p<0.01), and increased with the duration of diabetes (r=0.34, p<0.05), but not significantly with HbAl-levels (r=0.21, p=0.19). Diabetics with AND had an earlier onset p<0.05) and a longer duration of (p<0.01) diabetes, decreased vibration sense (p<0.05), more frequent hypoglycaemic episodes (p<0.05), intermittent claudication (p<0.01), a higher resting heart rate (p<0.05), and a shorter treadmill time (p<0.05). Consequently, at maximal exercise their systolic (p<0.05) and diastolic (p=0.08) blood pressure increased less. With longer duration of diabetes, retinopathy (p

[Assessment of left ventricular ejection fraction by echocardiography].

A new simplified echocardiography method to assess left ventricular (LV) ejection fraction (EF), combining routine M-mode and 2-D echo, was used to measure LV size and evaluate regional wall motion. Echocardiography was performed prior to cardiac catheterization in 35 patients aged 38-69 years (mean 53+8 years). Of these, 14 had suffered an anterior myocardial infarction. At catheterization three patients had ventricular extrasystoles and were omitted from data analysis. The new echo method is a simplification of a model used by Quinones et al. Furthermore, the same measurements were also used to calculate EF by the cube, Teichholz, ellipse, and bullet methods. Compared to the average EF determined by LV angiography of 58±17%, EF by the above echocardiography methods in the same respective order was 58±16, 70±14 (p<0.001), 61±15 (p<0.05), 62±13 (p<0.01) and 62±13% (p<0.01), respectively. The respective correlations (r-values) with angiography were 0.93, 0.87, 0.87, 0.91 and 0.91. Thus, compared with LV angiography the new simplified echocardiography method showed the best agreement and correlation, while other methods compared less favorably.

Incidence and prevalence of type 1 (insulin-dependent) diabetes mellitus in Icelandic children 1970-1989.

Through use of primary and secondary data sources for registration and validation, the incidence and prevalence of Type 1 (insulin-dependent) diabetes mellitus in children aged 0-14 years in Iceland has been completely ascertained for the years 1970-1989. The age-adjusted mean annual incidence per 100,000 for the 20-year period was 9.4 (95% confidence interval 7.8-11.3); similar for boys (9.9; 7.7-12.7) and girls (8.8; 6.7-11.5). Between 1970-1979 the incidence was 8.0 (6.0-10.6) and between 1980-1989 it was comparable at 10.8 (8.4-13.8) (p greater than 0.10). By Poisson regression analysis the variation in incidence was related to age at diagnosis (p less than 0.001), while a linear trend for calendar year at diagnosis did not reach statistical significance (p = 0.07). A quadratic curve, however, better described the temporal variation in incidence (p less than 0.05). The total prevalence per 1,000 by the end of 1979 and 1989 was similar, 0.45 (0.30-0.65) and 0.57 (0.40-0.79), respectively. In conclusion, this study confirms that both the incidence and prevalence of childhood Type 1 diabetes in Iceland are low compared to the other Nordic countries. The findings may suggest a causative role for environmental factors that are not related to latitude or ambient temperature.

Addition of sodium to the nonionic contrast medium iohexol during coronary angiography in man. Lack of electrocardiographic or hemodynamic effects.

It has recently been claimed that lack of sodium in nonionic contrast media may increase the risk of ventricular arrhythmias during coronary angiography. Thus, the influence of sodium addition to the nonionic contrast medium iohexol was studied in 75 patients with severe coronary heart disease. The study design was randomized, parallel and double-blind, and iohexol was given either with or without addition of NaCl (28 mmol/l). Both formulations induced a transient drop in arterial blood pressure, and prolongation of the QT interval and QRS duration at 10 s only (p less than 0.01). The electrical QRS axis was significantly changed by the coronary artery injections after 10 s, but not later. No differences between iohexol with and without NaCl were observed for any of the variables studied. No serious arrhythmias were observed. Thus, the addition of NaCl (28 mmol/l) to iohexol did not influence the electrocardiographic or hemodynamic changes induced by iohexol during coronary angiography.

Respiratory gas exchange during treadmill exercise testing: reproducibility and comparison of different exercise protocols.

Ten subjects performed 4 maximal exercise tests to evaluate reproducibility and effects of treadmill inclination on submaximal and maximal oxygen consumption. They performed a standard Bruce protocol twice, and 1 protocol with progressive speed increase with constant, or without, inclination. At maximal exercise there was no significant difference between the protocols in oxygen consumption, respiratory gas exchange ratio, minute ventilation, plasma lactate, serum potassium or heart rate. Exercise time and treadmill distance were shorter than Bruce protocol with inclination, and considerably prolonged without. Reproducibility for Bruce protocol was good for group comparison of oxygen consumption throughout exercise. The individual variations for oxygen consumption were small at maximal exercise, but were considerable at rest and at the lowest exercise steps, this was slightly improved by analysing longer sampling time. Thus, measurement of oxygen consumption is reliable for group analysis, but interpretation must be careful in individuals unless maximal exercise is obtained. Treadmill inclination may be adjusted according to individual preferences.

Arterial and venous measurement in resting forearm of metabolic indicators during rest and leg exercise.

We compared the levels of various metabolic indicators in arterial and venous forearm blood during maximal treadmill leg exercise, and the subsequent 9 min in nine volunteers aged 31-56 years. At maximal exercise plasma lactate was 13.2 +/- 3.1 mmol l-1 arterially, while venous was 41% lower, but increased more than arterial after exercise. There was a linear relationship between arterial and venous samples during and after exercise, but not at baseline. Plasma pyruvate increased on the arterial side from 49 +/- 8 to 172 +/- 30 mumol l-1 at maximal exercise, maximal venous was 21% lower. Free fatty acids were not different at rest, but decreased during exercise by 52 and 38% on the arterial and venous side. There was no relationship between arterial and venous levels. Changes in these three variables occurred significantly earlier on the arterial side. Arterial cyclic AMP rose from 97.3 +/- 28.4 to 262.7 +/- 67.5 nmol l-1 from rest to exercise, and was linearly inversely related to the decrease in free fatty acids. The mean venous pH was lower than arterial at rest, but was the same as arterial at maximal exercise and after. Thus, venous plasma lactate and pyruvate, but not free fatty acids, are linearly related to arterial measurements during maximal exercise, while pH is identical. Non-working muscle modifies exercise-induced changes, and therefore venous and arterial forearm blood sampling give more information than either alone.

Clinical and haemodynamic features in relation to severity of aortic stenosis in adults.

The main symptoms of aortic stenosis (AS), angina pectoris, dyspnoea, and syncope/effort dizziness, are thought to reflect the severity of AS. This assumption is based on studies in relatively young patients, and may not apply to older age groups. Thus, in 100 consecutive adults (age 41-79 years) referred to cardiac catheterization with suspected AS, clinical and haemodynamic variables were assessed in relation to significant (less than or equal to 0.50 cm2 m-2) (n = 70) and nonsignificant AS (n = 30), and to symptoms. Prevalence of symptoms, functional class, and systolic murmur grade greater than or equal to 3, was similar in the groups. However, patients with significant AS more often had an abnormal second heart sound, electrocardiographic left ventricular (LV) hypertrophy with strain, severe echocardiographic aortic valve calcification, and increased LV wall thickness. Multivariate analysis identified an abnormal second heart sound, and aortic calcification grade, as independent predictors of significant AS. When the Doppler mean gradient was added to the analysis, it became the best predictor. Angina pectoris (n = 74) was related to coronary artery disease, but not to severity of AS. However, 31% of patients without angina also had coronary artery disease. Dyspnoea (n = 69) was only related to age, and syncope/effort dizziness (n = 26) was more frequent in women. Functional class grade was not related to severity of AS. Thus, in adults with assumed symptomatic AS, clinical symptoms do not predict severity of AS. Therefore, the decision for valve replacement should rely on Doppler assessment of the severity of AS. Furthermore, in adults with AS, coronary artery disease cannot be excluded without selective coronary angiography.