Successful radiofrequency ablation of accessory pathways with the first energy delivery: the anatomic and electrical characteristics

Successful ablation of accessory pathways has been achievedat the first energy delivery site in some patients, but factorspermitting success at the first site are unclear. Accessorypathway location, surface and endocardial electrogram characteristicsin each location were analysed and compared between the patientswith first site block (group A, 34 patients) and those in whommultiple sites (median seven sites) were required (group B,133 patients). No patients with right free-wall pathways hadfirst site block. In group A surface electrocardiograms weremore pre-excited (QRS duration: 132±20 vs 120 ±l7ms, P<0·0l). For left free-wall and septal pathways,the interval from the onset of the earliest delta wave on surfaceelectrocardiogram to local ventricular activation (QRS-V) wasmore negative and the local atrioventricular interval (AV) wasshorter in group A; the positive predictive value of a QRS-V0 ms, an AV 30 ms and the presence of a possible accessory pathwaypotential was 67% for left free-wall and of a QRS-V -10 ms withan AV 30ms was 100% for septal pathways. During retrograde mappingof concealed left free-wall and right anteroseptal pathways(first site block was not achieved in other locations) the positivepredictive value of a local ventriculoatrial interval 30 mswas 55%. Accessory pathway location correlated strongly with the chancesof first site block, suggesting that anatomical features areimportant. Maximizing pre-excitation may be of benefit in achievingfirst site block. Delivery of energy to a site with specialendocardial electrogram features was associated with an increasedlikelihood of first site block.     

Coronary risk factors in men occupationally exposed to vibration and noise

In a group of 481 men (group A ) exposed occupationally to vibration(exceeding by four times the permissible levels in the frequencyband 32–64–125 Hz) and noise (105–116 dB),and in a group of 303 men without contact with vibration andnoise at work (reference group R) the prevalence of coronaryrisk factors was assessed, Socioeconomic status, level of occupationalphysical activity and family history of heart disease were comparablein the two groups. Mean blood pressure values and the percentage with hypertensionwere significantly higher in the exposed than in the referencegroup(P0.01). Overweight and hypertrigliceridemia occurred lessfrequently in group A than in group R(P0.01 and P0.05 respectively).The prevalence of hypercholesterolaemia and smoking habits wassimilar in both groups. The results suggest that vibration andnoise may be factors which increase the risk of coronary heartdisease.     

Coronary risk factors in men occupationally exposed to vibration and noise

In a group of 481 men (group A ) exposed occupationally to vibration(exceeding by four times the permissible levels in the frequencyband 32–64–125 Hz) and noise (105–116 dB),and in a group of 303 men without contact with vibration andnoise at work (reference group R) the prevalence of coronaryrisk factors was assessed, Socioeconomic status, level of occupationalphysical activity and family history of heart disease were comparablein the two groups. Mean blood pressure values and the percentage with hypertensionwere significantly higher in the exposed than in the referencegroup(P0.01). Overweight and hypertrigliceridemia occurred lessfrequently in group A than in group R(P0.01 and P0.05 respectively).The prevalence of hypercholesterolaemia and smoking habits wassimilar in both groups. The results suggest that vibration andnoise may be factors which increase the risk of coronary heartdisease.     

Subjective symptoms and well-being differ in women and men after myocardial infarction

The frequency of subjective cardiac and psychological complaintsamong men and women a year after a confirmed diagnosis of myocardialinfarction (MI) were compared. Among 660 survivors, 595 patientscompleted mailed questionnaires at home one year after the MI.There were 421 men, mean age 67.1±10.7 years, and 174women, mean age 72.1±10.6 years. Controlling for the significantly higher mean age among thewomen, the latter more often had a previous history of anginapectoris, 54.6% (P0.05) versus 42.9%, and heart failure, 24.7%versus 13.5% (P0.01). Despite these facts, the women were significantlyless often referred to CCU, 82.2% versus 91.7% (P0.05). Oneyear after the MI, controlling for differences in age and co-morbidity,women reported significantly higher frequencies of psychologicaland psychosomatic complaints, including sleep disturbances.These differences may have clinical implications for diagnosisand treatment of women with coronary heart disease.     

Effects of percutaneous balloon mitral valvuloplasty and exercise training on the kinetics of recovery oxygen consumption after exercise in patients with mitral stenosis

Aims Kinetics of recovery oxygen consumption after exercise playsan important role in determining exer-cise capacity. This studywas performed to assess the kinetics of recovery oxygen consumptionin mitral stenosis and evaluate the effects of percutaneousballoon mitral valvuloplasty and exercise training on the kinetics. Methods and Results Thirty patients with mitral stenosis (valve area 1·0cm²)and same sized age- and size-matched healthy volunteers wereincluded for this study. All subjects performed maximal uprightgraded bicycle exercise. Thirty consecutive patients who underwentsuccessful percutaneous balloon mitral valvuloplasty (valvearea 1·5cm²and mitral regurgitation grade 2), were randomizedto an exercise training group or non-training group. The exercisegroup performed daily exercise training for 3 months. Half-recoverytime of peak oxygen consumption was significantly delayed inmitral stenosis as compared to normal subjects (120±42svs 59±5,P<0·01). Peak oxygen consumption (ml.min^–1.kg^–1)was significantly increased in both the training (16·8±4·9to 25·3±6·9) and non-training groups (16·3±5·1to 19·6±6·0) 3 months after percutaneousballoon mitral valvuloplasty. Half-recovery time of peak oxygenconsumption was significantly shortened in the training group(124±39 to 76±13,P<0·01), but not inthe non-training group (114±46 to 109±44s,P=0·12)at 3 months follow-up. The degrees of symptomatic improvementafter percutaneous balloon mitral valvuloplasty were more closelycorrelated with the changes of the half-recovery time of peakoxygen consumption than those of peak oxygen consumption. Conclusion Kinetics of recovery oxygen consumption was markedly delayedin mitral stenosis, which was improved after exercise trainingbut not after percutaneous balloon mitral valvuloplasty alone.These results suggest that adjunctive exercise training maybe useful for improvement of recovery kinetics and subjectivesymptoms after percutaneous balloon mitral valvuloplasty.     

Lack of correlation between haemodynamic and cardiopulmonary exercise capacity improvement after catheter-balloon mitral valvuloplasty

The long-term effects of percutaneous transvenous mitral commissurotomyon exercise capacity and ventilation were investigated to determinewhether a dissociation between haemodynamic improvement andexercise capacity increase occurs in patients with mitral stenosis.Eighteen patients aged 45 ± 12.3 years (mean ±SD) with symptomatic mitral stenosis performed a symptom-limitedbicycle exercise test while respiratory gases were measuredbefore and 6 months after percutaneous transvenous mitral commissurotomy.The mitral valve area increased from 1.07 ±0.22 to 1.98±0.67 cm². P<0.0001 and the mean mitral gradient decreasedfrom 12.9 ±4.5 to 5.3±4.8mmHg, P<0.001, withouta significant increase in cardiac output index (from 2.64 ±0.55 to 2.77 ± 0.56 l. min_{– 1}. m_{– 2}, P= ns).This haemodynamic improvement was still present at the 6-monthfollow-up catheterization. Mean exercise workload and peak oxygenuptake increased 6 months after percutaneous transvenous mitralcommissurotomy from 88.3 ± 28.1 to 97.8 ± 25.1watts, P= 0.01, and from 18.1 ± 5.3 to 19.9 ±4.8 ml. kg_{– 1}.min_{– 1}, P<0.05. Total ventilation,ventilatory equivalents and oxygen pulse at the end of the exercisetest remained unchanged Correlations between peak oxygen orexercise capacity improvement and mitral valve area increasewere poor (r= 0.27, P= ns, r= 0.24, P=ns). This clear dissociationbetween haemodynamic improvement and improvements in minor exercisecapacity after percutaneous transvenous mitral commissurotomysuggests that peripheral alterations persist. Future studiesin which patients are trained after valvuloplasty may be helpful.     

Inferior ST segment depression as a useful marker for identifying proximal left anterior descending artery occlusion during acute anterior myocardial infarction

To determine whether or not ST segment deviation on admissionelectrocardiograms can identify patients with anterior acutgemyocardial infarction due to proximal left anterior descendingartery occlusion, the magnitude and location of ST segment elevationor depression were compared between patients with proximal leftanterior descending artery occlusion (group A, n=47) and thosewith distal left anterior descending artery occlusion (groupB, n =59). ST segment depression in each of the inferior leadswas significantly greater in group A than in group B. The incidenceof ST segment depression 1 mm in each of the inferior leads(II; 81% vs 27%, III; 85% vs 54%, aVF; 87% vs 47%, P<0.01)was significantly higher in group A than in group B. In addition,the incidence of ST segment depression 1 mm in all of the inferiorleads was significantly greater in group A than in group B (77%vs 22%, P<0.01). In group A, maximal ST segment elevationwas more frequent in lead V alone (43% vs 14%, P<0.01). GroupA had greater ST segment elevation in lead a VL than group B,and the incidence of ST segment elevation 1 mm in lead a VLwas significantly higher in group A than in group B (66% vs47%, P<0.05). ST segment depression 1 mm in all of the inferiorleads was most valuable for identifying group A patients (77%sensitivity and 78% specificity). In contrast, the maximal STsegment elevation in lead V₂ alone or ST segment elevation 1 mm in lead a VL had a low diagnostic value (43% sensitivityand 86% specificity, 66% sensitivity and 53% specificity, respectively).In conclusion, this study indicates that analysis of ST segmentdeviation in the inferior leads is useful for identifying patientswith acute anterior myocardial infarction due to proximal leftanterior descending occlusion.     

Autonomic balance in patients with angina and a normal coronary angiogram

The pathophysiology of angina pectoris in patients with a normalcoronary angiogram is not clear. Furthermore, the pathophysiologicalimpact of ST changes in syndrome X is controversial. The purposeof this study was to investigate cardiac autonomic function,by measuring 24 h heart rate variability, in patients with andwithout electrocardiographic evidence of ischaemia during exercise. Thirty-two patients with angina pectoris, a normal coronaryangiogram, echocardiogram, hyperventilation test and gastro-oesophagealinvestigation were studied. Fourteen healthy subjects servedas controls. Fifteen patients had significant ST segment depressionduring stress testing, whereas 17 had no electrocardiographicsigns of ischaemia. Heart rate variability was calculated as(1) mean RR= mean of all normal RR intervals, (2) the differencein mean RR level between when awake and when asleep (mean RRwake-sleep)—a tentative index of sympathetic activation,(3) the standard deviation (SD)—a broad band measure ofautonomic balance, and (4) a percentage of successive RR intervaldifferences 6% (pNN6%)—an index of vagal modulation. Thecoronary vascular resistance was measured at rest and duringpacing. Mean RR and autonomic indexes did not differ between patientswith a positive exercise test and controls (831/884 m 24 h SD125/134 m pNN6% 6.715.4%, respectively). Patients with a normalexercise test had shorter mean RR (758 ms vs 844 m P<0.05)and significantly reduced 24-h SD (103 ms vs 134 m P<0.05)than controls, whereas values for vagal index (6.5% vs 5.4%)did not differ from healthy controls. Mean RR wake-sleep alsotended to be lower in patients with a normal exercise test (–125 ms vs – 173 ms) compared to controls (P<0.1). Patientswith a positive exercise test had a significantly attenuatedreduction in coronary vascular resistance during pacing in comparisonto patients with a normal exercise test (–0.131–0.26mmHg x min. ml^{– 1}; P<0.05). The findings suggest the occurrence of general elevated sympatheticactivation in angina patients with a normal exercise test. Patientswith a positive exercise test exhibited no signs of autonomicdysfunction although these patients had altered coronary vascularresistance indicating microvascular angina. This supports thesuggestion that patients with a normal exercise test constitutean independent pathophysiological entity.     

Right and left ventricular ejection fraction and left ventricular volume changes at rest and during exercise in normal subjects

The effect of exercise upon right and left ventricular ejectionfractions (RVEF and LVEF) as well as the changes upon left ventricularend-diastolic and end-systolic volume indices (LVEDVI and LVESVI)were investigated. Twenty-two normal subjects were studied atrest and during upright submaximal exercise. RVEF was determinedusing a first-pass method. LVEF was measured using multiplegated blood pool imaging. During the exercise test ECGs remained normal. HR and BP increasedsignificantly (P<0.01). RVEF increased from 44%±4(mean±SD) to 60%±6 (P<0.001). LVEF increasedfrom 62%±6 to 76±5 (P<0.001). A wider scatterwas observed in RVEF than in LVEF. There was a 14% increasein LVEDV-index and a 14% decrease in LVESV-index (P<0.001).A multiple regression analysis with RVEF as the dependent variableand HR, systolic BP, LVEF, LVEDV-index and LVESV-index as independentvariables showed a significant correlation between RVEF andLVEF and systolic BP (P<0.05). Our data provide insight intothe mechanisms by which the pump performance is increased innormal subjects. The central mechanisms observed are the Starlingeffect and an increase in contractility of the myocardium. Thisis connected in the general circulation to an increase in afterload,indicating a redistribution of blood from the vascular bedsto the muscles and to the heart.     

Determination of left ventricular wall thickness and muscle mass by intravenous digital subtractionangiocardiography: validation of the method

Left ventricular (LV) wall thickness and muscle mass are importantmeasures of LV hypertrophy. In 24 patients LV end-diastolicwall thickness and muscle mass were determined (two observers)by digital subtraction angiocardiography (DSA) and conventionalLV angiocardiography (LVA). Wall thickness was determined overthe anterolateral wall of the left ventricle according to thetechnique of Rackley (method 1) or by planimetry (method 2).Seventeen patients were studied at rest and seven during dynamicexercise. Wall thickness correlated well between LVA and DSA;the best correlations were obtained by a combined subtractionmode using either method 1 or 2 (method 1, r0–80; method2,r0. 75). The standard error of estimate of the mean (SEE) wasslightly lower for method 2 ( 10%) than for method 1 ( 13%).DSA significantly overestimated wall thickness by 5–7%with method 1 and underestimated by 12–14% with method2. Muscle mass correlated well between LVA and DSA; the SEEwas 15% for method 1 and 12% for method 2. Overestimation ofmuscle mass by DSA was 7–11% with method 1 and underestimationwas 13–15% with method 2.It is concluded that LV wallthickness can be determined accurately by DSA with an SEE rangingbetween 10 and 13%. Determination of LV muscle mass is slightlyless accurate and the SEE is slightly larger ranging between13 to 17%. With method 1, wall thickness and muscle mass wereover estimated and with method 2 underestimated.     

Lipoprotein(a) as a risk predictor for cardiac mortality in patients with acute coronary syndromes

Aims Raised lipoprotein(a) concentrations are considered to be arisk factor for atherothrombotic diseases. We examined whetherbaseline concentrations were a risk factor for an adverse outcomein patients admitted with acute coronary syndromes. Methods and Results Five hundred and nineteen patients admitted with suspected acutecoronary syndromes were studied and followed prospectively fora median of 3 years. The prognostic significance of a baselinelipoprotein(a) concentration of 30mg.dl^–1or lower forsubsequent cardiac death was assessed in patients with myocardialinfarction (266) and unstable angina (197) and compared withother variables in regression models. In patients with myocardialinfarction, a baseline lipoprotein(a) concentration of 30mg.dl^–1wasassociated with a 62% increase in subsequent cardiac death comparedto the lower concentration group (29·8% vs 18·6%,Log rankP=0·04). In a multivariate regression model abaseline lipoprotein(a) concentration of 30mg.dl^–1retainedits significance as an independent predictor of cardiac death(P=0·037). In patients with unstable angina, baselineconcentrations of 7·9mg.dl^–1were found to be significantpredictors of cardiac death in univariate (P=0·021) andmultivariate (P=0·035) regression models. Conclusion Baseline lipoprotein(a) concentrations in patients admittedwith acute coronary syndromes are associated with an increasedrisk of cardiac death. For patients with myocardial infarctiona concentration of 30mg.dl^–1appears appropriate as a riskdiscriminator; for patients admitted with unstable angina, however,much lower concentrations of lipoprotein(a) appear to be prognosticallyimportant.     

Evaluation and prognostic significance of left ventricular diastolic function assessed by Doppler echocardiography in the early phase of a first acute myocardial infarction

AIM: To study the prognostic significance of left ventricular diastolicfunction evaluated by transmitral and pulmonary venous flowvelocities obtained in the early phase of a first acute myocardialinfarction in relation to later development of congestive heartfailure. METHODS: Pulsed Doppler echocardiography of transmitral and pulmonaryvenous flow was assessed in 65 consecutive patients with a firstmyocardial infarction within 1 h of arrival in the coronarycare unit. RESULTS: A univariate regression analysis identified age, left ventricularejection fraction 45%, mitral E deceleration time 130 ms, E/Aratio >1·5, peak pulmonary venous atrial flow velocity30 cm . s^–1 and a difference between mitral and pulmonaryvenous atrial flow duration >0 ms as variables significantlyrelated to the development of congestive heart failure. However,in a multivariate analysis only mitral E deceleration time 130ms and age were significant independent variables related tothe development of congestive heart failure during the firstweek following a first acute myocardial infarction. CONCLUSION: Assessment of left ventricular diastolic function complementsmeasurements of systolic function in the evaluation of cardiacfunction, and mitral deceleration 130 ms best identifies patientsat risk of development of congestive heart failure followingacute myocardial infarction.     

Differences in restenosis propensity of devices for transluminal coronary intervention: A quantitative angiographic comparison of balloon angioplasty, directional atherectomy, stent implantation and excimer laser angioplasty

With the increasing clinical application of new devices forpercutaneous coronary revascularization, maximization of theacute angiographic result has become widely recognized as akey factor in maintained clinical and angiographic success.What is unclear, however, is whether the specific mode of actionof different devices might exert an additional independent effecton late luminal renarrowing. The purpose of this study was toinvestigate such a difference in the degree of provocation ofluminal renarrowing (or ‘restenosis propensity’)by different devices, among 3660 patients, who had 4342 lesionssuccessfully treated by balloon angioplasty (n=3797), directionalcoronary atherectomy (n= 200), Palmaz-Schatz stent implantation(n= 229) or excimer laser coronary angioplasty (n= 116) andwho also underwent quantitative angiographic analysis pre- andpost-intervention and at 6-month follow-up. To allow valid comparisonsbetween the groups, because of significant differences in coronaryvessel size (balloon angioplasty=2.62±0.55 mm, directionalcoronary atherectomy= 3.28±0.62 mm, excimer laser coronaryangioplasty= 2.51±0.47 mm, Palmaz-Schatz=3.01±0.44mm;P<0.0001), the comparative measurements of interest selectedwere the ‘relative loss’ in luminal diameter (RLoss=losslvessel size) to denote the restenosis process, and the‘relative lumen at follow-up’ (RLfup=minimal luminaldiameter at follow uplvessel size) to represent the angiographicoutcome. For consistency, lesion severity pre-intervention was representedby the ‘relative lumen pre’ (RLpre=minimal luminaldiameter prelvessel size) and the luminal increase at interventionwas measured as ‘relative gain’ (relative gain=gainl vessel size). Differences in restenosis propensity betweendevices was evaluated by univariate and multivariate analysis.Multivariate models were constructed to determine relative lossand relative lumen at follow-up, taking account of relativelumen pre-intervention, lesion location, relative gain, vesselsize and the device used. In addition, model-estimated relativeloss and relative lumen at follow-up at given relative lumenpre-intervention relative gain and vessel size, were comparedamong the four groups. Significant differences were detectedamong the groups both with respect to these estimates, as wellas in the degree of influence of progressively increasing relativegain, on the extent of renarrowing (relative loss) and angiographicoutcome (relative lumen at follow-up), particularly at higherlevels of luminal increase (relative gain). Specifically, lesionstreated by balloon angioplasty or Palmaz-Schatz stent implantation(the predominantly ‘dilating’ interventions) wereassociated with more favourable angiographic profiles than directionalatherectomy or excimer laser (the mainly ‘debulking’interventions). Significant effects of lesion severity and location,as well as the well known influence of luminal increase on bothluminal renarrowing and late angiographic outcome were alsonoted. These findings indicate that propensity to restenosis afterapparently successful intervention is influenced not only bythe degree of luminal enlargement achieved at intervention,but by the device used to achieve it. In view of the clinicalimplications of such findings, further evaluation in largerrandomized patient populations is warranted.     

Time domain analysis of the signal averaged electrocardiogram in patients with a conduction defect or a bundle branch block

Doubts have been expressed about the clinical usefulness oftime domain analysis of the signal averaged electrocardiogramin patients with prolonged QRS complex duration. We studied147 patients using a signal averaged ECG (40–250 Hz) whoseQRS complex was longer than 100 ms. A baseline electrophysiologystudy was also performed in 128 of these patients. Seventy-sevenpatients had a minor (QRS <120 and >100 ms) conductiondefect. Thirty-seven of these 77 had either induced or spontaneoussustained ventricular tachycardia (group I) and 40 had no sustainedventricular tachycardia (group II). Seventy patients had a major(QRS120 and >100 ms) conduction defect, 44 of whom had sustainedventricular tachycardia (group A). The remaining 26 withoutthis condition formed Group B. Group I compared to group IIpatients had a longer filtered QRS duration (120.8 ±14 vs 104.5 ± 9.5 ms, P<0.001), a longer low amplitudesignal duration (41 ± 12.1 vs 31 ± 12.6 ms, P<0.0001)and a lower root mean square of the last 40 ms of the filteredQRS complex (27 ± 29.8 vs 35 ± 25.3 µV,P=ns). Group A compared to group B had a longer filtered QRSduration (157.7±20.2 vs 140.7± 15.7 ms, P<0.001),a longer low amplitude signal duration (57.3 ±24.9 vs37.8 ± 20.3 ms P<0.001) and a lower root mean squareof the last 40 ms of the filtered QRS complex (14.3 ±11.2 vs 22.0 ± 10.5 1 P<0.01). Using conventionallate potential criteria, the sensitivity and specificity ofthe signal averaged ECG for the detection of sustained ventriculartachycardia patients with a minor conduction defect were 89%and 75%, respectively. The same criteria applied to patientswith a major conduction defect were sensitive (sensitivity:87%) but non-specific (specificity: 50%). However, by usingmodified late potential criteria, such as the presence of twoof any of the following three signal averaged parameters: filteredQRS duration 145 ms, low amplitude signal duration 50 ms,root mean square of the last 40 ms of the filtered QRS complex17.5µV, we derived a non-optimal but still acceptablecombination of sensitivity (68%) and specificity (73%). We concludethat traditional late potential criteria can be applied in patientswith a minor conduction defect, but modification of these criteriais necessary to derive useful clinical information for riskstratification of patients with a QRS complex duration 120ms.     

Biplane transoesophageal echocardiography, transthoracic Doppler, and magnetic resonance imaging in the assesment of coarctation of the aorta

This study compared flow-sensitive magnetic resonance imagingwith biplane transoesophageal echocardiography in combinationwith continuous wave Doppler from the suprasternal notch inpatients with native coarctation or after surgical repair. Twenty patients (mean age 33 years, range 17–60) wereinvestigated, of whom 15 had undergone surgery at mean age 13years, range 5.43. Peak and mean flow in the ascending and descendingaorta as well as coarctation peak velocity were determined withthe magnetic resonance imaging phase contrast technique. Coarctationpeak velocity was also measured by Doppler from the jugulum.Magnetic resonance imaging axial sections as well as biplanetransoesophageal echocardiography were used to measure the smallestdiameter of the constricted segment. Sixteen healthy volunteers,mean age 36 years, range 22.63, provided reference values formagnetic resonance imaging determined volume of flow in theaorta. Peak flow in the descending aorta was 9.2 ±3.71.min ^{– 1} (reference 130 ± 2.5, P<0.01) and meanflow 3.1 ±0.9 I. min^{– 1} (reference 3.4 ±0.8,P>0.05). The ratio of descending-to-ascending peak flow was0.54 ±0.17 (reference 0.69 ± 0.10, P<0.01)and mean flow 0.68 ± 0.15 (reference 0.69 ± 0.08,P>0.05). The coarctation velocity was slightly higher withDoppler than with magnetic resonance imaging (+ 0.24 ±0.44 m. s^{– 1}, 95% confidence interval +0.45 to + 0.02m.s^{– 1}, P= 0.05). The coarctation diameter was slightlylarger with magnetic resonance imaging than with transoesophagealechocardiography (1.4 ±3.5 mm, 95% confidence interval+ 3.1 to – 0.3 mm, P= 0.11). Both methods are suitable for the assessment and follow-up ofcoarctation of the aorta Flow assessment with magnetic resonanceimaging provides a hitherto unavailable measure with which toassess the severity of obstruction.     

The prognostic value of exercise testing early after myocardial infarction in patients treated with thrombolytics

Exercise testing early post A MI was evaluated as a predictorof re infarction in patients treated with thrombolytics. AMIpatients exercise-tested prior to discharge were included inthe study (n = 178). The patients were followed for 2.9±0.9years (mean±1 SD) for the development of new cardiacevents defined as cardiac death or reinfarction. Cox regressionanalysis of clinical and exercise test variables showed thatthere was significant predictive value of treating heart failurewith drugs from two or more therapeutic groups (P<0.001;hazard ratio 9.4 (3.1–28.2) (estimate and 95% confidenceinterval)), such as those with a previous history of myocardialinfarction (P = 0.001; hazard ratio 4.0 (1.7–9.6)) andof significant ST depression (P = 0.029; hazard ratio 2.5 (1.1–5.7)).Significant ST depression could be substituted by the ST/HRindex (P = 0.042; hazard ratio 2.8 (1.2–6.8)). The exercise test had independent but limited prognostic valuein AMI patients treated with thrombolytics. The ST/HR indexdid not improve the predictive value of the exercise test.     

Angioscopic evaluation of prolonged vs standard balloon inflations during coronary angioplasty: A randomized study

To study the immediate effects of prolonged total balloon inflationduring PTCA, 41 patients (44 lesions) with chronic-stable anginawere randomized for prolonged sequential inflations (three tofive inflations of 3 to 5 min each, for a total duration of 12 min, group 1, n=20 lesions) or ‘standard’ sequentialinflations (three to five inflations of 1 min each, for a totalduration of 3 min, group 2, n-24 lesions). The mean durationof total balloon inflation time was 958 ± 129 s in group1 vs 205 ±46 s in group 2. Results of angioplasty wereassessed on both angiography and percutaneous transluminal coronaryangioscopy performed immediately after the procedure. High qualityimaging of the coronary lumen and lesion morphology was possibleon angioscopy in all patients without any complications. Post-PTCAangiographic percent diameter stenosis was significantly lessin group 1 compared to group 2: 26 ± 10% vs 36 ±8% (P<0.05). On angioscopy, flaps were seen in 16 patientsin group 2, but in only six in group 1 (P<0.02). There wasno difference in the incidence of thrombi on angioscopy betweenthe two groups (group 1: nine cases, group 2: 10 cases). Sensitivityof angiographic detection of flaps and thrombi was poor: 10%and 12% respectively. One patient in each group developed alongitudinal dissection, detected on both angiography and angioscopy. Conclusions: (1) prolonged sequential balloon inflations leadto less residual luminal stenosis after PTCA, with a decreasedincidence of intimal flaps in comparison with standard inflations.(2) Post-PTCA transluminal coronary angioscopy is safe and offersbetter assessment of luminal effects of PTCA than angiography.     

Age-related mortality, clinical heart failure, and ventricular fibrillation in 4259 Danish patients after acute myocardial infarction

AIMS: To evaluate the prognosis of patients 80 years old, we analyseda large, community-based population with acute myocardial infarctionwho received intensive observation and similar pharmacotherapyregardless of age. METHODS AND RESULTS: In a 12-year period, before the introduction of thrombolysis,4259 consecutive patients hospitalized with acute myocardialinfarction from the same hospital in Denmark were prospectivelyregistered. Their complications and mortality in hospital, and1 and 5 years after discharge were analysed retrospectively.Overall, in-hospital mortality was 11% for patients less than<50 years old, 22% for patients 60–69 years old and43% for patients 80 years old. Two thirds of patients 80 yearsold had heart failure, and cardiogenic shock was twice as commonin this age group than in patients 60–69 years. Heart failure was a strong independent risk, factor for post-dischargemortality, particularly in the oldest age groups. Four out ofeight patients 80 years survived one year if discharged aliveafter experiencing in-hospital ventricular fibrillation. CONCLUSION: The life-saving potential of preventing or treating heart failureseems considerable even in the oldest patient groups. Patients80 years old who survive in-hospital ventricular fibrillationhave an acceptable prognosis 1 year post-discharge.     

Influence of aortic regurgitation on the assessment of the pressure half-time and derived mitral-valve area in patients with mitral stenosis

The influence of aortic regurgitation on the Doppler assessmentof pressure half-time (T) and on the derived calculation ofthe mitral-valve area has not yet been adequately evaluatedin patients with mitral stenosis and associated aortic regurgitation.Therefore this study was undertaken to verify the accuracy ofthe T method for the noninvasive estimation of mitral-valvearea in patients with mitral stenosis and associated aorticregurgitation. Data were obtained from 31 selected patientswho underwent cardiac catheterization within 24 h of the noninvasiveexamination. From the Doppler velocity curve, T was calculatedas the interval between the peak transmitral velocity and velocity/. Mitral-valve area was measured fromthe T with a computerized system using the equation: 220/T,in cm². Calculation of the mitral-valve area at catheterizationwas derived applying the modified Gorlin formula. Mean mitral-valvearea, as determined at catheterization, ranged from 0.5 to 2.8cm² (1.3±0.6). Mean mitral-valve area, as calculatedby continuous-wave Doppler, ranged from 0.7 to 2.7 cm² (1.5± 0.6). Linear-regression analysis of data revealed agood correlation between Gorlin and Doppler measurements ofthe mitral-valve area (r = 0.90, SEE = 0.28 cm², P<0.001,y = 1.0x + 0.2). Doppler showed a systematic overestimate ofthe mitral-valve area (26%) in patients with mitral stenosisand aortic regurgitation as compared to the Gorlin formula.The overestimate of continuous-wave Doppler was even greater(39%) in a subgroup of patients with 2 + or 3 + angiographicaortic regurgitation. Thus the Doppler T method still providesaccurate noninvasive estimates of mitral-valve area in patientswith mitral stenosis and associated aortic regurgitation. However,when the degree of aortic regurgitation is significant, Dopplercan lead to important overestimation of the mitral orifice size.     

Peak oxygen uptake during exercise in mitral stenosis with sinus rhythm or atrial fibrillation: lack of correlation with valve area: A study in 70 patients

Although the haemodynamic response during submaximal supineexercise in mitral stenosis has been well described, the determinantsof peak oxygen uptake during maximal upright exercise are poorlycharacterized and may differ in sinus rhythm and atrial fibrillation.Seventy patients with isolated mitral stenosis underwent Doppler-echocardiographyand bicycle exercise with respiratory gas analysis. Forty-twopatients were in sinus rhythm (Group I) and 28 in atrial fibrillation(Group II). Peak oxygen uptake it was 21·3±5·6ml. min^–1 kg^–1 in group I and 18·1 ±5·1 ml min^–1 kg^–1 in group II (P<0·05).There was no significant correlation between indices of exercisetolerance (exercise duration, ventilatory threshold, peak oxygenuptake, indexed peak oxygen uptake, peak oxygen pulse) and valvearea or gradient in either group. Indexed peak oxygen uptakewas not correlated to oxygen pulse but was linearly related(r=0·43) to heart rate ( heart rate =peak heart rate=restheart rate) in Group I but not in Group II. Thus, in patientswith mitral stenosis, no correlation was found between the mitralvalve area or the gradient at rest and maximal upright exercisetolerance, suggesting that peripheral adaptation and, in sinusrhythm, chronotropic reserve, are important compensatory mechanisms.