Normal coronary flow reserve in patients with mitral valve prolapse, a positive exercise test and normal coronary arteries

We studied 12 patients (eight females and four males), ages30–46 years, with echocardiographically documented mitralvalve prolapse and clinical suspicion of coronary artery disease,based on a history of chest pain (five patients), angina-likepain (three patients), a positive exercise stress electrocardiogram(12 patients) and a focally positive thallium-201 stress perfusionscan (three patients), who were referred for cardiac catheterizationand found to have normal coronary arteries. Ten patients withoutevidence of heart disease served as controls. In all mitralvalve prolapse patients, coronary flow velocity reserve wasdetermined successively in the left anterior descending, leftcircumflex and right coronary arteries as the ratio of the maximun(after intracoronary papaverine) to the resting mean coronaryflow velocity. Coronary flow reserve values were fairly similarin the mitral valve prolapse and control patients; all 12 mitralvalve prolapse patients had normal coronary flow reserve (3.5)in all three coronary arteries with no significant differencesamong the arteries tested Mean values ± 1 standard deviationof the coronary flow reserve (mitral valve prolapse vs controlpatients) were 4.7 ± 0.5 vs 4.6 ± 0.6 for theleft anterior descending, 4.6 ± 0.4 vs 4.6 ± 0.3for the left circumflex and 4. ± 0.4 vs 4.4 ±0.5 for the right coronary artery (all P=non-significant). Thesubsets of mitral valve prolapse patients with different clinical‘ischaemic’ manifestations were similar in termsof the calculated coronary flow reserve in all three major epicardialcoronary arteries. In conclusion, this study demonstrated that an inadequate regionalcoronary flow reserve does not account for the clinical manifestationsof myocardial ischaemia and positive exercise tests in patientswith mitral valve prolapse and normal coronary arteries.     

Comparison between regional myocardial perfusion reserve and coronary flow reserve in the canine heart

Diameter stenosis and flow reserve are indices of morphologicaland functional severity of coronary artery stenosis. Flow reservecan be determined at coronary arterial or at myocardial level.In the presence of functional collateral circulation, coronaryflow reserve and myocardial perfusion reserve may differ. We studied coronary flow, coronary flow reserve and myocardialperfusion reserve in an open chest dog model with intact collateralcirculation, before and after induction of coronary artery stenosis.Coronary flow was determined with perivascular ultrasonic flowprobes and myocardial perfusion reserve from digital angiographicimages, in the stenotic as well as the adjacent non-stenoticcoronary arteries. Before induction of a stenosis, a significant correlation existedbetween coronary flow reserve and myocardial perfusion reserveof the left anterior descending (r=0·59; P<0·005)and the left circumflex arteries (r=0·84, P<0·005).In stenotic arteries, coronary flow reserve and myocardial perfusionreserve decreased significantly (P<0·005), but inthe adjacent non-stenotic arteries coronary flow reserve wasnot affected Myocardial perfusion reserve in the non-stenoticadjacent left anterior descending artery decreased significantly(P<0·05) and no correlation was found between coronaryflow reserve and myocardial perfusion reserve, whereas in theadjacent non-stenotic left circumflex artery there was no statisticallysignificant decrease (4·1 ± 1·6 3·5± 1·4) but there was a good correlation betweencoronary flow reserve and myocardial perfusion reserve (r=0·85;P<0·005). This study demonstrates that, in the presence of a stenosisand functioning collateral circulation, coronary flow reserveis not a reliable predictor of myocardial perfusion reserve;both parameters provide mutually complementary information.     

Clinical utility of two-dimensional magnetic resonance angiography in detecting coronary artery disease

AIMS: The accuracy of magnetic resonance angiography in detectingproximal coronary artery stenoses is unclear. We postulatedthat fast magnetic resonance angiography is capable of (1) imagingproximal coronary arteries, and (2) detecting stenoses of 50%of their luminal diameter. METHODS AND RESULTS: Thirty-five patients, referred for analysis of angina pectoris,underwent both conventional angiography and magnetic resonanceangiography of coronary arteries. A fast k-space segmented gradient-echotechnique was used during breath-holds. Two observers, blindedto the results of conventional angiography, independently analysedthe magnetic resonance studies for (1) length of visualizedsegments, and (2) presence of signal voids indicative of stenoses.From 140 proximal arteries, 15 (11%) were excluded because ofincomplete imaging or degraded image quality. Mean length ofthe visualized segments was 9±4 mm for the left main,62±16 mm for the left anterior descending, 21±9mm for the left circumflex and 89±32 mm for the rightcoronary artery. Sensitivity for detecting 50% luminal diameterstenoses was 0·00 for the left circumflex, 0·53for the left anterior descending coronary artery, 0·71for the RCA and 1·00 for the left main artery. Specificityvaried from 0·73 for the left anterior descending coronaryartery to 0·96 for the left circumflex. Inter-observeragreement was 0·90. CONCLUSION: Thus, segmented magnetic resonance angiography is capable ofnon-invasive imaging of proximal coronary anatomy. Its goodaccuracy in detecting left main coronary artery disease, intermediateaccuracy in detecting right coronary artery and left anteriordescending coronary artery stenoses, and low accuracy in detectingleft circumflex lesions fit within a range of sensitivitiesand specificities found by others. Further technical advancesare necessary to make the technique clinically robust.     

Mitral valve prolapse in patients with coronary artery disease. Echocardiographic-angiographic correlation.

Echocardiography was performed in 25 consecutive patients with angina pectoris and angiographically demonstrable coronary artery disease. Left ventricular echograms detected late or pansystolic mitral valve bowing suggesting of mitral valve proplapse in 6/25 (24%). Left ventricular angiography showed prolapse of the posterior mitral leaflet in 15/25 (60%), including 5 detected by echocardiography. Significant triple vessel coronary disease was present in 11 of 15 patients with prolapsed mitralvalve. In each of the latter a greater than 90 per cent obstructive lesion was noted in at least one coronary artery: right coronary artery, 9 subjects (82%); left circumflex coronary artery, 5 patients (33%); and left anterior descending coronary artery, 4 patients (27%). Of 15 subjects with angiographic evidence of mitral valve prolapse, 13 had left ventricular asynergy-inferior or inferoposterior in 8 subjects (62%) and anterior or anteroapical in 5 subjects (38%). Eleven subjects had vectorcardiographic evidence of transmural myocardial infarction-inferior or inferoposterior in 9 (82%) and anteroseptal in 2 (18%). A single subject with mitral valve prolapse had mild mitral regurgitation. It is concluded that: (1) coexisting prolapse of the posterior mitral valve leaflet and coronary artery disease is usually associated with triple vessel obstructive lesions, (2) severe right coronary disease, inferior left ventricular wall asynergy, and inferior myocardial infarction are important angiographic and vectorcardiographic correlates, and (3) echocardiography will detect such mitral valve prolapse in only one-third of affected cases.     

Functional characteristics of myocardial bridging: A combined angiographic and intracoronary Doppler flow study

AIMS: Combined quantitative coronary angiography and intracoronaryDoppler flow velocity measurements were performed to study theunderlying haemodynamic mechanisms leading to myocardial ischaemiain patients with myocardial bridging in the absence of coronaryartery disease. METHODS AND RESULTS: In 42 symptomatic patients with myocardial bridging of the leftanterior descending coronary artery, quantitative coronary angiographywas used to measure absolute and relative vessel diameters duringsystole and diastole. In 14 patients, serial frame-by-framediameter quantification during a complete cardiac cycle wasperformed. Intracoronary blood flow velocities were determinedusing a 0·014 inch Doppler flow guide wire proximal,within, and distal to myocardial bridges, and coronary flowreserve was calculated. Quantitative coronary angiography revealeda maximal systolic lumen diameter reduction of 71 ± 16%with a persistent diameter reduction of 35 ± 13% duringmid-diastole. Flow velocities revealed increased average diastolicpeak flow velocities within myocardial bridges of 38·6± 19 cm. s^–1 vs 22·4 ± 7·7cm. s^–1 proximal and 18·6±4·6cm.s^–1 distal (P<0·001), which increased duringrapid pacing (64·7 ± 25 cm. s^–1, P<0·001vs baseline). Coronary flow reserve distal to myocardial bridgeswas 2·3 ± 0·9 (vs 2·9 ± 0·9proximal, P<0·05). There was a characteristic Dopplerflow profile within myocardial bridges with an early diastolicovershoot, which was further augmented during rapid pacing. CONCLUSION: Myocardial bridging is characterized by a delay in diastoliclumen gain and a concomitant increase in diastolic intracoronaryDoppler flow velocities, which are enhanced by rapid pacing.In combination with a reduced coronary flow reserve and anginalsymptoms these findings support the concept of a haemodynamicallysignificant obstruction to coronary flow due to myocardial bridgingin a selected subset of patients.     

Early results after mitral valvuloplasty for pure mitral regurgitation

In this study we present the results of 105 consecutive patientswith pure mitral regurgitation who underwent surgical treatment.In all patients mitral regurgitation was associated with mitralvalve prolapse: 54 patients underwent mitral valvuloplasty and51 patients mitral valve replacement. Clinical assessment and echocardiography were used as follow-upcriteria at one year after surgery. After mitral valvuloplasty,NYH A decreased from 2.7±0.8 to 1.1±0.7 (P<0.01)and workload capacity increased from 65±28% to 96±25%(P<0.001); left endsystolic atrial dimension and enddiastolicdimension decreased from 6.2±0.8 to 4.8±1.2 cm(P<0.001) and from 7.2±1.3 to 5.9±0.8 cm (P<0.01);ventricular contraction fraction did not change significantly. After mitral valve replacement, clinical and echocardiographicimprovement was significant but less remarkable than after valvuloplasty;ventricular contraction fraction fell from 39±7% to 29±8%in contrast to patients undergoing mitral valvuloplasty in whomno significant change occurred. Complications were rare in both groups though only a minorityof patients undergoing mitral valvuloplasty received anticoagulants.We conclude that mitral valvuloplasty in patients with puremitral regurgitation associated with mitral valve prolapse givesexcellent results, particularly regarding left ventricular functionwhen compared with the patients after mitral valve replacement.     

Early results after mitral valvuloplasty for pure mitral regurgitation

In this study we present the results of 105 consecutive patientswith pure mitral regurgitation who underwent surgical treatment.In all patients mitral regurgitation was associated with mitralvalve prolapse: 54 patients underwent mitral valvuloplasty and51 patients mitral valve replacement. Clinical assessment and echocardiography were used as follow-upcriteria at one year after surgery. After mitral valvuloplasty,NYH A decreased from 2.7±0.8 to 1.1±0.7 (P<0.01)and workload capacity increased from 65±28% to 96±25%(P<0.001); left endsystolic atrial dimension and enddiastolicdimension decreased from 6.2±0.8 to 4.8±1.2 cm(P<0.001) and from 7.2±1.3 to 5.9±0.8 cm (P<0.01);ventricular contraction fraction did not change significantly. After mitral valve replacement, clinical and echocardiographicimprovement was significant but less remarkable than after valvuloplasty;ventricular contraction fraction fell from 39±7% to 29±8%in contrast to patients undergoing mitral valvuloplasty in whomno significant change occurred. Complications were rare in both groups though only a minorityof patients undergoing mitral valvuloplasty received anticoagulants.We conclude that mitral valvuloplasty in patients with puremitral regurgitation associated with mitral valve prolapse givesexcellent results, particularly regarding left ventricular functionwhen compared with the patients after mitral valve replacement.     

Syncope and ventricular arrhythmias in hypertrophic cardiomyopathy are not related to the derangement of coronary microvascular function

Non-sustained ventricular tachycardia on Holter and syncopehave been considered risk factors for sudden death in hypertrophiccardiomyopathy. AIMS: In these patients the coronary vasodilator reserve is impaireddespite normal coronaries, so we evaluated the correlation betweenthe severity of coronary vasodilator reserve impairment andthe occurrence of syncope and non-sustained ventricular tachycardia. METHODS AND RESULTS: Eighty-four patients with hypertrophic cardiomyopathy (62 males,age 43±12 years) had a two-dimensional echocardiographicstudy and a 48-h Holter. Myocardial blood flow was measuredby positron emission tomography, at baseline and after dipyridamole,and the coronary vasodilator reserve was computed as dipyridamolemyocardial blood flow/baseline myocardial blood flow. In 27patients, subendocardial and subepicardial myocardial bloodflow was measured in the septum and the subendocardial/subepicardialratio was computed. Twenty of 84 patients had at least one syncopalepisode, and 26 had at least one run of non-sustained ventriculartachycardia on Holter. Baseline and dipyridamole myocardialblood flow, coronary vasodilator reserve, and baseline and dipyridamolesubendocardial/subepicardial myocardial blood flow ratio weresimilar in patients with and without syncope and with and withoutnon-sustained ventricular tachycardia on Holter. However, patientswith non-sustained ventricular tachycardia had larger left ventricularend-diastolic (47±6 vs 44±5 mm, P<0·05)and end-systolic diameters (30±6 vs 27±4 mm, P<0·05). CONCLUSIONS: (1) Coronary vasodilation is not more severely impaired in patientswith hypertrophic cardiomyopathy and syncope or non-sustainedventricular tachycardia. (2) The left ventricle is more dilatedin hypertrophic cardiomyopathy with non-sustained ventriculartachycardia.     

Assessing coronary stenosis. Quantitative coronary angiography versus visual estimation from cine-film or pharmacological stress perfusion images

Visual judgment of stenosis severity from cine-film or single-photonemission computed tomographic dipyrida-mole perfusion imageswas compared to assessment of stenosis severity as measuredwith digital quantitative coronary angiography. Thirty patientswith angiographically verified single-vessel disease underwentdipyridamole thallium stress testing within 90 days of angiography. RESULTS: A percent diameter stenosis of 50%, a percent area stenosisof 75% and a stenotic flow reserve of <3·75 measuredby quantitative coronary angiography (CMS, version 1·1,Medis Inc.) corresponded to haemodynamically significant stenosisas evaluated by visual estimates from cine-film or perfusionimages. Quantitative coronary angiography percent diameter stenosis(51·2% ± 12·6%) correlated closely (r=0·74)but underestimated significantly visual assessment of stenosisseverity from cine-film (69·3% ±21·2% p=0·0001).However, quantitative coronary angiography percent area stenosis(74·7% ± 11·7%) more closely reflectedvisual estimates from cine-film (P=0·19). Quantitativecoronary angiography stenotic flow reserve showed the highestpositive and negative predictive value regarding visual estimatesfrom cine-film (88%, 86%) or perfusion images (88% 64%) followedby percent diameter stenosis (86% 75% 86% 56%) and percent areastenosis (87% 80% 87% 60%), respectively. CONCLUSION: Evaluation of coronary lesions by quantitative coronary angiographycorresponds closely with visual estimates from cine-film andhaemodynamic significance as evaluated by dipyridamole perfusionimages. (Eur Heart J 1996; 17: 1167–1174)     

Mitral valve prolapse in coronary artery disease.

Mitral valve motion, left ventricular segmental contraction and severity of arterial stenosis were analyzed in 92 patients with coronary artery disease and 28 patients with "atypical chest pain" and normal coronary arterio-rams. Mitral valve motion was evaluated for the presence or absence of leaflet prolapse. Segmental contraction was evaluated by calculating the percent shortening of six chords of the left ventricle measured from right anterior oblique ventriculograms. The severity of disease in each coronary vessel (left anterior descending, left circumflex and right coronary) was graded on a scale of 1 (0 to 30 percent stenosis) to 5 (complete occlusion). Mitral valve prolapse was not suspected clinically but observed angiographically in 15 of 92 patients with coronary artery disease and in 5 of 28 patients with normal coronary arteriograms. In nine patients with coronary artery disease, the prolapse was restricted to the posterior leaflet, in five it was in both the anterior and the posterior leaflets and in one patient in the anterior leaflet only. Mitral regurgitation was noted in seven patients with coronary artery disease; it was mild in six and moderate in one. Among the patients with coronary artery disease, 12 of the 15 (80 percent) with mitral valve prolapse had left ventricular asynergy compared with 63 of the 77 (82 percent) without valve prolapse. The mean scores for severity of disease in the left anterior descending, circumflex and right coronary arteries were, respectively, 4.2, 2.5 and 3.2 in the patients with valve prolapse and 4.2, 2.2 and 3.5 in those without prolapse. In summary, there was no significant correlation between mitral valve prolapse and distribution of coronary arterial obstructions or abnormal patterns of left ventricular segmental contraction. There was a high frequency of mitral valve prolapse in patients with severe coronary artery disease and in those with normal coronary arteriograms and atypical chest pain.     

Different mechanisms of mitral regurgitation in acute and chronic forms of coronary heart disease

Contradictory two-dimensional echocardiographic findings havebeen reported in relation to the role of prolapse of the mitralvalve and lack of systolic leaflet coaptation in mitral regurgitationsecondary to coronary heart disease. A prospective study of22 patients with chronic coronary heart disease and mitral regurgitationshowed the following: Inferior akinesia was detected in 14 (64%),fibrosis of the posteromedial papillary muscle in 10 (45%),and prolapse of the mitral valve in nine (41%). A combinationof the three signs was seen in six patients (27%). Lack of systolicleaflet coaptation was seen in only two patients, both withanterior myocardial infarction. When these results are comparedwith those reported in the literature, it is apparent that inacute coronary heart disease, lack of leaflet coaptation isfrequently visualized (P <0.0l) and fibrosis of the postero-medialpapillary muscle and prolapse of the mitral valve are lacking(P<0.01). A unitary explanation of all forms of mitral regurgitation incoronary heart disease is misleading; mechanisms of mitral regurgitationin coronary heart disease depend on the clinical presentation-acuteor chronic, the site of infarction, and the presence of cardiacdilatation.     

Failure to demonstrate myocardial ischaemia in patients with angina and normal coronary arteries. Evaluation by continuous coronary sinus pH monitoring and lactate metabolism

Visual judgment of stenosis severity from cine-film or single-photonemission computed tomographic dipyrida-mole perfusion imageswas compared to assessment of stenosis severity as measuredwith digital quantitative coronary angiography. Thirty patientswith angiographically verified single-vessel disease underwentdipyridamole thallium stress testing within 90 days of angiography. RESULTS: A percent diameter stenosis of 50%, a percent area stenosisof 75% and a stenotic flow reserve of <3·75 measuredby quantitative coronary angiography (CMS, version 1·1,Medis Inc.) corresponded to haemodynamically significant stenosisas evaluated by visual estimates from cine-film or perfusionimages. Quantitative coronary angiography percent diameter stenosis(51·2% ± 12.6%) correlated closely (r=0·74)but underestimated significantly visual assessment of stenosisseverity from cine-film (69·3% ±21·2% p=0·0001).However, quantitative coronary angiography percent area stenosis(74·7% ± 11·7%) more closely reflectedvisual estimates from cine-film (P=0·19). Quantitativecoronary angiography stenotic flow reserve showed the highestpositive and negative predictive value regarding visual estimatesfrom cine-film (88%, 86%) or perfusion images (88% 64%) followedby percent diameter stenosis (86% 75% 86% 56%) and percent areastenosis (87% 80% 87% 60%), respectively. CONCLUSION: Evaluation of coronary lesions by quantitative coronary angiographycorresponds closely with visual estimates from cine-film andhaemodynamic significance as evaluated by dipyridamole perfusionimages. (Eur Heart J 1996; 17: 1167–1174)     

Balloon mitral valvotomy: comparison between antegrade Inoue and retrograde non-transseptal techniques

AIMS: The results of percutaneous mitral valvotomy performed by theantegrade transseptal method using the Inoue balloon (n=1000;group 1) and by the retrograde non-transseptal technique usinga polyethylene balloon (n=100; group 2) were compared in a retrospective,non-randomized study. METHODS AND RESULTS: Both the groups were similar with respect to baseline characteristics.The success rate was 95% in group 1 and 93% in group 2. Therewas a significant increase in mitral valve area estimated byGorlin's equation (Group 1: from 0·8 ± 0·5to 2·1 ± 0·8 cm²; Group 2: from 0·8± 0·3 to 1·9 ± 0·8 cm², bothP<0·001) and by Doppler echocardiography using thepressure half-time method (Group 1: from 0·9 ±0·4 to 2·2 ± 0·6 cm²; Group 2: from0·9 ± 0·3 to 2·0 ± 0·7cm², both P<0·001). However, the calculated immediatepost-valvotomy mitral valve area was larger with the Inoue technique(2·1 ± 0·8 vs 1·9 ± 0·8cm²; P<0·02). Results were considered optimal whenthe mitral valve area increased to 1·5 cm², the percentageincrease was 50, and mitral regurgitation was 2/4. Out of thetotal successful procedures, optimal results were obtained in95% patients in Group 1 and 94% in Group 2. Incidence of significantmitral regurgitation (grade 3/4) was similar in two groups (Group1: 4% vs Group 2: 5%, P=ns). A significant left to right atrialshunt (Qp/Qs 1·5:1) in 2·5% and tamponade in2% of cases occurred exclusively with the Inoue technique, whileconduction disturbances, such as transient (<24 h) left bundlebranch block (28%) and complete heart block (2%) were notedwith the retrograde technique (Group 2). Local complicationswere significantly higher in Group 2 (3% vs 0·5%, P<0·01).The procedure time with the Inoue technique was shorter thanwith the retrograde (Group 1: 15 ± 8, range 10 to 35min; Group 2: 22 ± 14, range 15 to 45 min, P=0·05).Echocardiographic follow-up at 1 year showed no significantdifference in mitral valve area between the two groups (Group1 (n=300): 1·8 ± 0·8 vs Group 2 (n=60):1·9 ± 0·9 cm²; P=0·3). CONCLUSION: Balloon mitral valvotomy using the Inoue balloon and the retrogradenon-transseptal technique results in significant immediate haemodynamicand symptomatic improvement. The Inoue technique achieved alarger immediate post-valvotomy mitral valve area, but the differencewas not apparent at 1 year follow-up. Incidence of significantmitral regurgitation was similar with both the techniques; however,local complications occurred more frequently with the retrogradetechnique. Both techniques may complement each other in technicallydifficult cases.     

Prolapse of the mitral valve: clinical spectrum and coronary arterial distribution

Coronary angiograms were reviewed in 31 patients with idiopathic prolapse of the posterior mitral leaflet. There were 19 males and 12 females, ranging in age from 33 to 69. The coronary artery which supplied the posterior descending branch was designated as dominant. There were 27 dominant right coronary arteries and 4 dominant left coronary arteries. Attention was paid to whether the origin of the vessel which courses in the posterior atrioventricular groove branch was from the right coronary artery or the left circumflex. In the dominant right coronary artery group, the arterioventricular groove branch arose from the right coronary artery alone in 6 and from the left circumflex alone in 1 patient, and in 20 patients, from both. In the dominant left coronary artery group, the atrioventricular groove branch arose from the left coronary artery in all 4 patients. The frequency of dominant right coronary artery and left coronary and the origin of the atrioventricular groove branch did not differ in the patients with prolapse of the mitral valve from a control group of 30 patients similarly analyzed. In all instances, the atrioventricular groove branch arose from either the right coronary artery ro the left circumflex, or both. In no case was the arterioventricular groove branch totally absent. The results of this investigation do not support the thesis, previously advanced by others, that prolapse of the mitral valve is related to absence of the left circumflex coronary artery, but indicate a normal range of variation in coronary arterial distribution.     

Simplified percutaneous mitral valvuloplasty with the Inoue balloon

Background Percutaneous mitral valvuloplasty with the Inoue balloon isconventionally performed with double vascular access: arterialand venous. However, in patients with a good echogenic windowit may be performed with venous access only and the proceduremonitored by 2D-echocardiography and colour flow mapping. Thisshould result in early ambulation and hospital discharge withreduced arterial complications. Aims To compare retrospectively the immediate results of percutaneousmitral valvuloplasty with the Inoue balloon in two groups ofpatients: Group I: venous access only (no arterial access, n=102)and Group II: conventional double vascular access (arterialand venous access, n=275). Methods and Results The baseline characteristics of the two groups were comparablefor age, sex, clinical, echo-cardiographic, radiological andhaemodynamic variables. The mitral valve area (Group I: 1·1±0·3to 1·85±0·5cm²vs Group II: 1·05±0·2to 1·85±0·5cm², P=ns) and transmitral gradient(Group I: 11±4 to 4·7±2mmHg vs Group II:12±4 to 4·8±2mmHg, P=ns) before and aftermitral valvuloplasty were not statistically different. A goodimmediate result, defined as mitral valve area >1·5cm²andmean mitral gradient <5mmHg with mitral regurgitation 2+at the end of the procedure, was observed in 77% of the casesin the venous-only group and 79% in the double access group(P=ns). The incidence of severe mitral regurgitation (GradeIII or IV) was not statistically significant. Procedural duration(71±24min vs 109±26min, P<0·01), fluoroscopictime (12·5±5·5min vs 18·5±6min,P<0·01) and hospital stay (2·8±15 daysvs 4·8±2·6 days, P<0·001) weresignificantly shorter in the venous-only group than in the conventionalInoue series. Conclusion Single venous access balloon mitral valvu-loplasty is as equallysafe and effective as double vascular access. The additionaladvantages of single venous access are shorter procedural duration,fluoroscopic time and hospital stay. We recommend that it beperformed by an experienced operator (minimum of 100 trans-septalpunctures) in patients without major thoracic deformity anda good echogenic window.     

Mechanisms of adenosine-induced epicardial coronary artery dilatation

BACKGROUND: In order to ascertain whether human adenosine-induced dilatationof epicardial arteries is direct or flow-mediated, we comparedthe effects of intracoronary adenosine infusion on epicardialcoronary arteries with those produced by dypiridamole, a selectivearteriolar vasodilator. METHODS AND RESULTS: In 24 patients with angiographically normal coronary arteries,coronary blood flow velocity was measured by a Doppler wireduring intracoronary infusion of adenosine or dipyridamole,which is known to increase intramyocardial adenosine concentration.Coronary angiograms were obtained at baseline and immediatelyafter the end of each infusion period; coronary diameters 5mm distal to the wire tip were measured by computer-assistedquantitative coronary angiography. Peak coronary blood flowvelocities during adenosine or dipyridamole infusions were similar(52·0 ± 15·5 and 47·9 ± 24·2cm. s^–1, P=ns). Coronary diameters immediately after adenosineand dipyridamole infusions were similar and both higher thanthat at baseline (2·80 ± 0·63 and 2·80± 0·64 vs 2·44 ± 0·69 mm,P<0·05). The absolute and percentage increases ofcoronary artery diameters in response to adenosine were highlycorrelated to coronary blood flow velocity (R=0·622,intercept –0·10 ± 0·14, P=0·002and R=0·617 intercept –15·2 ± 9·9,P=0·001, respectively); similar correlations were foundin response to dipyridamole (R=0·708, intercept –0·44± 0·19, P<0·001 and R=0·649,intercept –13·5 ± 8·7, P<0·001,respectively). Finally the absolute and percentage changes ofcoronary artery diameters caused by adenosine were highly correlatedto those caused by dipyridamole (R=0·840, P<0·001and R=0·836, P<0·001 respectively). CONCLUSIONS: A significant correlation exists between epicardial coronaryvasodilation and coronary blood flow velocity during intracoronaryadenosine infusion, thus suggesting that epicardial coronaryvasodilation induced by adenosine is predominantly flow-mediatedrather than direct. This conclusion is supported by the observationthat similar findings were obtained using dipyridamole, whichcan only dilate epicardial coronary arteries indirectly, throughthe increase in coronary blood flow velocity caused by the inhibitionof intramyocardial adenosine re-uptake.     

Superiority of mitral valve repair in surgery for degenerative mitral regurgitation

OBJECTIVES: We aimed to assess the influence of type of operation on outcomein degenerative mitral regurgitation. METHODS: We compared outcomes in 278 consecutive patients who underwentmitral valve repair (167 patients), replacement with subvalvularpreservation (22 patients) and without subvalvular preservation(89 patients) for degenerative mitral regurgitation. RESULTS: There was a trend towards lower mortality with repair and replacementwith subvalvular preservation compared to replacement withoutsubvalvular preservation. Thirty-day mortality was 1·2%vs 0·0% vs 4·7% (ns) respectively. Six-year survivalwas, respectively, 67·8±7·4% (P=0·088)vs 80·8±11·0% (P=0·25 vs 63·3±5·9%for all-cause death, 78·5±6·8% (P=0·063)vs 95·5±4·4% (P=0·092) vs 67·6±5·9%for all complication-related death and 80·5±6·9%(P=0·076) vs 100·0±0·0% (P=0·045)vs 72· ± 5·8% for complication-relateddeath due to myocardial failure. Multivariate analysis confirmedindependent beneficial effects from repair compared to replacementwithout subvalvular preservation on complication-related death(hazard ratio 0·42, P=0·010) and death from myocardialfailure (hazard ratio 0·40 P=0·014), and fromrepair compared to mechanical replacement on thromboembolism(hazard ratio 0·45, P=0·029) and anticoagulation-relatedhaemorrhage (hazard ratio 0·19, P=0·026). CONCLUSIONS: Mitral valve repair is superior to replacement. The greatestsurvival advantage is in reduced mortality from myocardial failure.Repair should be the operation of choice for degenerative mitralregurgitation.     

The reactivity of the contralateral artery at the time of balloon dilation during coronary angioplasty

The response of the contralateral arteries was investigatedduring balloon angioplasty of the left anterior descending artery.Thirty patients were studied. Coronary arteriograms were obtainedat baseline, during maximal balloon inflation and at the endof the procedure. Luminal diameter was measured by a quantitativecoronary arteriography analysis system. During balloon inflationthe luminal diameter of the proximal segment of the right coronaryartery increased by 24 ± 6% (P<0·05), and thatof the left circumflex artery increased by 0·6 ±6% (P=ns). Both returned to near baseline values after angioplasty.in patients with increased collaterals during balloon inflationthe left circumflex proximal segment increased more significantlythan in patients with unchanged collaterals. The luminal diameterof the distal segment of the right coronary artery increasedby 9 ± 8% (P<0·001) and that of the left circumflexartery by 8 ± 11% (P<0·01) during balloon inflation,returning to near baseline values after angioplasty. Thus, vasodilation of the contralateral arteries during ballooninflation at the time of coronary angioplasty occurs mainlyin the distal segments and appears to be related to an increasein collateral filling.     

Physical training improves exercise capacity in patients with mitral stenosis after balloon valvuloplasty

BACKGROUND: Haemodynamic measurements taken at rest and during exerciseshowed that percutaneous transvenous mitral commissurotomy resultsin both acute and long-term improvement. However, the time lagbefore there is an increase in exercise and in peak oxygen uptakeappears to be delayed and irregular. PATIENTS AND METHODS: To assess the potential of physical training to restore betterphysical capacity after percutaneous transvenous mitral commissurotomy,26 patients with mitral stenosis were studied after the procedure.The group was split into two. Thirteen underwent a 3-month rehabilitationprogramme, and the other 13, who did not, acted as controls. RESULTS: The mitral valve orifice area increased similarly, from 1·;12±017to 1·88 ±0·28 cm² in the training groupand from 1·04±0·16 to 1·88±0·19cm² in the control group. Cardiopulmonary parameters were similarbefore percutaneous transvenous mitral commissurotomy (peako₂: 19·9±2·4 vs 18·9±4·5ml. min^–1. kg^–1; peak workload: 94·6±29·3vs 96·1±25 watts; o₂ at anaerobic threshold: 17±3·4vs 16·1±5·2 ml. .min^–1. kg^–1;all P=ns). Three months later the results were higher in thetraining group (peak o₂: 26·6±4·7 vs 21·6±3·8ml. min^–1. kg^–1, P=0·001; peak workload:125·4±26·6 vs 108·5±23 watts,p=0·03; o₂ at anaerobic threshold: 19·6±5·8vs 15·8±2·9 ml. min^–1. kg^–1;P=0·02). CONCLUSION: These results indicate that patients should take up exerciseafter successful percutaneous transvenous mitral commissurotomyfor better functional improvement.     

Colour Doppler echocardiographic assessment of regurgitant flow in mitral valve prolapse

Colour flow mapping was used to examine the pattern of regurgitantflow in 46 patients with mitral regurgitation due to mitralvalve prolapse. Valve morphology was assessed from the real-timetwo-dimensional image and the presence of mitral regurgitationwas determined from real time Doppler. On morphological criteria11 (24%) patients had isolated or predominant anterior leafletprolapse, 22 (48%) patients posterior and 13 (28%) patientsbi-leaflet prolapse. A single regurgitant jet was detected in43 patients (93%) and multiple jets in three (7%). The directionof the regurgitant jet was assessed in multiple views in twoorthogonal planes (antero-posterior and medial-lateral) definedin relation to the mitral valve leaflets. The regurgitant jetwas eccentric in the antero-posterior plane of the mitral leafletsin 40 of 45 (89%) cases and in the medial-lateral plane in 36of 40 (90%) cases. Posterior leaflet prolapse was usually associatedwith antero-medially directed jets, anterior leaflet prolapsewith postero-central or postero-lateral jets and bi-leafletprolapse with predominantly postero-medial jets. In a subgroupof patients with significant mitral regurgitation and an eccentricregurgitant jet, a ‘swirling’ effect was producedwith late systolic flow in the body of the left atrium towardthe mitral valve. Colour flow mapping in patients with mitral regurgitation dueto mitral valve prolapse demonstrated eccentric jets in mostpatients. The direction of regurgitant flow appeared to dependgreatly on the dynamic anatomy of the mitral valve leafletsduring systole. Although a single jet was detected in most patients,multiple jets did occur in a minority.