Left heart catheterization; the clinical importance of findings

Left heart catheterization using the transbronchial route to obtain pressures in the left atrium and left ventricle was used successfully in 29 cases with no mortality or morbidity. It was found to be useful in differentiating between mitral stenosis and mitral insufficiency, as well as determining the amount of aortic stenosis present when there was involvement of the aortic valve. The technique was also helpful in determining which is the predominant lesion when there is a disease of the aortic and mitral valves. In two patients in a series of 29, data obtained by left heart catheterization forestalled operation on the basis of a mistaken diagnosis of mitral stenosis when actually no mitral valvular disease was present. In another eight patients, the predominant lesion was found to be mitral stenosis rather than mitral insufficiency as it was thought to be before catheterization. In two patients, who had only systolic murmurs, catheterization revealed mitral stenosis rather than mitral insufficiency. In four patients who were thought to have mixed valvular disease, left heart catheterization showed only aortic valvular disease.     

LEFT HEART CATHETERIZATION—The Clinical Importance of Findings

Left heart catheterization using the transbronchial route to obtain pressures in the left atrium and left ventricle was used successfully in 29 cases with no mortality or morbidity. It was found to be useful in differentiating between mitral stenosis and mitral insufficiency, as well as determining the amount of aortic stenosis present when there was involvement of the aortic valve. The technique was also helpful in determining which is the predominant lesion when there is a disease of the aortic and mitral valves.In two patients in a series of 29, data obtained by left heart catheterization forestalled operation on the basis of a mistaken diagnosis of mitral stenosis when actually no mitral valvular disease was present. In another eight patients, the predominant lesion was found to be mitral stenosis rather than mitral insufficiency as it was thought to be before catheterization. In two patients, who had only systolic murmurs, catheterization revealed mitral stenosis rather than mitral insufficiency. In four patients who were thought to have mixed valvular disease, left heart catheterization showed only aortic valvular disease.     

The Diagnosis of Mitral Stenosis

The diagnosis of classical mitral stenosis is easy, but many pitfalls lead to over-diagnosis or under-diagnosis. These have been considered in detail and variations in symptoms and signs have been illustrated by case histories. Such variations include: (1) Embolism producing the Leriche syndrome; (2) mitral stenosis with insignificant hemodynamic effect; (3) myxoma masquerading as mitral stenosis; (4) mitral stenosis without apical murmurs, and (5) mitral stenosis with a systolic murmur predominant or alone. In cases of combined mitral and aortic stenosis, the history, radiographic configuration, and incidence of hemoptysis, edema, bronchitis, embolism and atrial fibrillation resemble such findings in cases of isolated mitral stenosis, but the auscultatory signs of the latter may be obscured. The degree of aortic stenosis is difficult to determine in cases of combined stenosis. In the diagnosis of re-stenosis the condition of the valve at the first commissurotomy, the precise procedure performed and the degree of regurgitation produced are of prime importance. Congenital mitral stenosis is rare and is associated with a high incidence of other defects.     

Muscular Subaortic Stenosis: The Initial Left Ventricular Inflow Tract Pressure as Evidence of Outflow Tract Obstruction

Two types of intraventricular pressure differences within the left ventricle of man are described. The first is encountered in cases of muscular (or fibrous) subaortic stenosis, in which the outflow tract pressure distal to the stenosis (and proximal to the aortic valve) is low, whereas all pressures recorded in the left ventricle proximal to the stenosis, including that just inside the mitral valve (the initial inflow tract pressure) are high.The second type of intraventricular pressure difference may be recorded in patients without muscular subaortic stenosis when a heart catheter is advanced to the left ventricular wall in such a manner that it becomes imbedded or entrapped by cardiac muscle in systole. Such an entrapped catheter records a high intraventricular pressure that is believed to reflect intramyocardial tissue pressure, which normally exceeds intracavitary pressure. In such cases the initial inflow tract pressure is not high and is precisely equal to the outflow tract systolic pressure, i.e. both are recording intracavity pressure. This type of intramyocardial to intracavitary pressure difference may also be encountered in the left ventricle of dogs.The recent suggestion that intraventricular pressure differences in the left ventricle of cases of muscular subaortic stenosis are due to catheter entrapment by cardiac muscle is refuted by using the initial inflow tract pressure as the means of differentiation between the two types of intraventricular pressure differences outlined.     

Recommended Criteria for Cardiac Catheterization in Patients with Aortic Valve Disease

Criteria for selection of patients with aortic valve disease for cardiac catheterization are described, based on a study of 81 cases. Children with aortic stenosis warrant catheterization at the time when the clinical diagnosis is made, but in adults this examination may be deferred until symptoms appear or left ventricular hypertrophy is recognized. In patients with pure aortic insufficiency catheterization may be deferred until symptoms appear. When severe stenosis and insufficiency co-exist, the valve is usually heavily calcified. Thirty-seven per cent of patients with aortic valve disease have co-existing mitral lesions and these patients are usually women, are fibrillating and, as a rule, have atrial enlargement in contrast to those with aortic valve disease only. On rare occasions, patients with mitral valve disease have clinically silent but angiographically demonstrable aortic insufficiency; therefore, aortography should precede open-heart correction of a mitral lesion so as to detect minor degrees of aortic insufficiency.     

Observations on the Value of Mitral Commissurotomy: An Analysis of Long-Term Results

Long-term follow-up of patients subjected to mitral commissurotomy permits evaluation of the late efficacy of this operation and the causes of subsequent deterioration in some cases.Three hundred and eighty-nine patients operated upon for mitral stenosis from 1950 to 1957 were studied. Of these, 89 died, 38 were lost to follow-up and 262 were re-examined.Results for the postoperative period of five to 12 years were satisfactory in 204 patients (77%) and unsatisfactory in 58 (22%). The possible causes of deterioration were studied separately.A second commissurotomy was performed on 23 patients (8.7%), because of re-stenosis thought to be due to a rheumatic process in one and to fibrotic scarring in nine, and because of an inadequate opening in 13.Mitral commissurotomy is a palliative operation, but is definitely useful in cases of tight mitral stenosis.The duration of improvement in patients with a functionally adequate opening is related to the state of the myocardium and to the possibility of rheumatic fever recurrences. Because of the risk of fibrotic restenosis, the possibility that a second commissurotomy might be required should be considered in each patient subjected to this operation.     

Valvular heart disease; the role of cardiac catheterization in preoperative evaluation

Cardiac catheterization studies performed in research laboratories showed that advanced mitral stenosis is associated with a characteristic dynamic pattern which is reversible by mitral valvulotomy. In the process of the selection of patients for mitral valvulotomy, occasionally there are instances in which a decision cannot be reached on the basis of ordinary clinical methods of examination. In some such cases cardiac catheterization may be of decisive value by demonstrating, or by failing to demonstrate, the dynamic pattern of mitral stenosis. Cases in which this diagnostic procedure is most often helpful are those of mild mitral stenosis and those in which there are combined valvular defects.     

Restenosis Following Mitral Valvoplasty

Nineteen seriously disabled patients were operated upon a second time (using closed-heart technique) for recurrence of symptoms of mitral stenosis. The hospital mortality rate was 10.5%; there was one late death. Ten patients (52%) were well and working six months to five years after the second operation. In considering the cause of restenosis it was noted that nine patients had inadequate opening of the mitral valve at first operation. In five cases (26%) rheumatic activity appeared to be solely responsible for restenosis. In a further four cases (21%) it was considered that rheumatic activity was a contributing cause of restenosis. The diagnosis of rheumatic activity and the place of open heart procedures in the treatment of restenosis are discussed.     

Modeling mitral valve stenosis: A parametric study on the stenosis severity level

New computational techniques providing more accurate representation of human heart pathologies could help uncovering relevant physical phenomena and improve the outcome of medical therapies. In this framework, the present work describes an efficient computational model for the evaluation of the ventricular flow alteration in presence of mitral valve stenosis. The model is based on the direct numerical simulation of the Navier–Stokes equations two-way coupled with a structural solver for the left ventricle and mitral valve dynamics. The presence of mitral valve stenosis is mimicked by a single-parameter constraint acting on the kinematics of the mitral leaflets.Four different degrees of mitral valve stenosis are considered focusing on the hemodynamic alterations occurring in pathologic conditions. The mitral jet, generated during diastole, is seen to shrink and strengthen when the stenosis gets more severe. As a consequence, the kinetic energy of the flow, the tissues shear stresses, the transvalvular pressure drop and mitral regurgitation increase. It results that, as the stenosis severity level increases, the geometric and effective orifice areas decrease up to 50% with respect the normal case due to the reduced leaflets mobility and stronger blood acceleration during the diastolic phase. The modified intraventricular hemodynamics is also related to a stronger pressure gradient that, for severe stenosis, can be more than ten times larger than the healthy valve case. These computational results are fully consistent with the available clinical literature and open the way to the virtual assessment of surgical procedures and to the evaluation of prosthetic devices.     

A fatal free floating thrombus in left atrium

An 81 year old woman, diagnosed with rheumatic mitral valve disease and atrial fibrillation ten years previous, was admitted due to a right carotid transient ischemic attack and a acute coronary syndrome. No ST elevation was noted in the region supplied by the anterior descending artery coronary (troponin T increased and anterolateral negative waves T). In recent years years, she had maintained with (anticoagulants) an INR of 2.5-3.5; however, in the previous month the INR had dropped to 1.8. The transthoracic echocardiography showed an anterolateral hypokinesis and a globular hyperechoic mass of 2 x 4 cm which appeared to be a free floating thrombus in the dilated left atrium. This occasionally caused occlusion of the mitral valve, which itself had a severe rheumatic stenosis of approximately 1 cm2. Due to the high risk of occlusion of the mitral valve and systemic embolisms, the mitral valve replacement and thrombectomy was recommend to the patient. The patient refused this treatment and subsequently died 5 days later. This case emphasizes the importance of a suitable level of anticoagulation (INR between 2,5 and 3,5) in patients with mitral stenosis and chronic atrial fibrillation. These cases have a the high risk of thromboembolism, and urgent surgery is mandatory when a free floating left atrial thrombus is observed.     

Long-term follow-up studies after homograft replacement of the mitral valve

Follow-up studies on 132 patients who have received fresh aortic homograft replacement of the mitral valve since May 1967 indicate good long-term function of the valve. Clinically the majority of patients are greatly improved and are free from the risks of long-term anticoagulant therapy. Hemodynamic studies performed on 13 patients at 25 to 41 months postoperatively showed a significant decrease in left atrial and pulmonary artery pressures with a small increase in cardiac output. Late deterioration of the homograft produced severe insufficiency in four cases and organic stenosis in two cases. Reasons for isolated deterioration are suggested.     

Probe for production and measurement of acute mitral regurgitant flow in dog.

A probe for production and measurement of acute mitral regurgitation in dogs is described. It consists of a tube that is introduced into the mitral valve through the left atrial appendage. Regurgitant flow through the tube is measured by an electromagnetic device. Variation of flow and zero flow are achieved by narrowing or occluding the tube with a rubber cuff. In animals weighing 30-50 kg, the probe does not produce significant mitral stenosis and the mitral leaflets fit closely around the probe during ventricular systole. The instantaneous relationship between mitral regurgitant flow (MRF) and the gradient between left ventricular and left atrial pressure shows a marked delay of MRF at the beginning and end of regurgitation. This delay can be attributed to some extent to electrical phase lag and to the small movement of the probe relative to the mitral valve during the cardiac cycle. Measurement of regurgitant stroke volume is affected by this movement only to a small extent.     

IDENTIFICATION OF LARGE LEFT ATRIAL THROMBUS BY CROSS-SECTIONAL AND M-MODE ECHOCARDIOGRAPHY

In addition to a typical pattern indicative of mitral stenosis, the M-mode echo-cardiogram of a patient with mitral valve disease revealed a broad band of dense echoes within an enlarged left atrial cavity that was suggestive of an intraatrial thrombus. Subsequent cross-sectional echocardiography demonstrated a globular cluster of echoes inside the left atrial cavity, thus corroborating our interpretation of the M-mode recording. When open mitral commissurotomy was performed, a large, partially calcified thrombus was found protruding from the posterior wall and left atrial appendage into the atrial cavity. Postoperative M-mode and cross-sectional echocardiography did not show the previously noted abnormal echoes within the left atrium.     

Two-dimensional echocardiography in the diagnosis of unusual left atrial myxomas

In two patients with atypical myxomas of the left atrium, two-dimensional echocardiography furnished valuable diagnostic information. In one patient, who had previously developed an embolism at the right brachial artery, M-mode echocardiography revealed an abnormal band of echoes within the left atrium. Two-dimensional echocardiography showed a globular cluster of echoes that remained within the left atrial cavity throughout the cardiac cycle; left ventricular angiography confirmed the ultrasonic findings of an intraatrial mass. At surgery, a calcified, nonprolapsing myxoma was excised from the interatrial septum. The second patient had clinical as well as M-mode echographic features of mitral stenosis. Cardiac catheterization showed a significant gradient across the mitral valve, but the left ventriculogram was normal except for an unusual pattern of mitral regurgitation. Subsequent two-dimensional echocardiography revealed a mass of echoes that prolapsed through the mitral valve during diastole. At surgery, a left atrial myxoma was found attached to the posterior mitral annulus. Our experience indicates that two-dimensional ultrasound is superior to conventional echocardiography for detecting unusual cardiac masses.     

MITRAL OR AORTIC COMMISSUROTOMY—Criteria for Selection of Patients

In the selection of patients for mitral commissurotomy, five separate categories are to be considered: (1) true mitral block with small heart and high pulmonary artery pressure, (2) mitral stenosis without mitral block, (3) mitral stenosis with subacute carditis, (4) mitral stenosis with marked cardiac hypertrophy, and (5) mitral stenosis with embolism.Surgical results are good to excellent provided adequate preoperative evaluation has eliminated the groups with subacute carditis, and those without mitral block. Cardiac catheterization is a valuable adjunct in difficult problems.     

成人动脉导管未闭合并重度二尖瓣返流的外科治疗

目的:探讨外科手术治疗成人动脉导管未闭(PDA)合并重度二尖瓣返流(MR)的疗效.方法:回顾性分析2009年1月至2011年1月在本中心实施外科手术治疗6例PDA合并MR患者的临床资料.5例实施PDA缝扎术和二尖瓣置换术,1例实施PDA缝扎术和二尖瓣成形术.分别于术前、术后1周、1月、3月和1年行超声心动图检查,观察并测定左室舒张末期内径(LVEDD)和左室射血分数(LVEF)等指标的变化.结果:6例术后PDA均无残余分流.心脏彩超检查显示,术后1周与术前相比,LVEDD显著缩小(P＜0.01),术后1个月较术后1周进一步缩小(P＜0.01),术后3个月与术后1个月比较以及术后1年和术后3月比较LVEDD有所减少,但差异无统计学意义.LVEF术后比术前有所降低,但差异无统计学意义.所有病例在术后随访中未出现栓塞和出血等并发症.结论:外科手术治疗PDA合并MR疗效满意.术前单纯重度MR患者易漏诊PDA,应尽可能明确诊断.     

Mitral or aortic commissurotomy; criteria for selection of patients

IN THE SELECTION OF PATIENTS FOR MITRAL COMMISSUROTOMY, FIVE SEPARATE CATEGORIES ARE TO BE CONSIDERED: (1) true mitral block with small heart and high pulmonary artery pressure, (2) mitral stenosis without mitral block, (3) mitral stenosis with subacute carditis, (4) mitral stenosis with marked cardiac hypertrophy, and (5) mitral stenosis with embolism. Surgical results are good to excellent provided adequate preoperative evaluation has eliminated the groups with subacute carditis, and those without mitral block. Cardiac catheterization is a valuable adjunct in difficult problems.     

Ventriculo-atrial gradient due to first degree atrio-ventricular block: a case report

Background

Isolated, asymptomatic first degree AV block with narrow QRS has not prognostic significance and is not usually treated with pacemaker implantation. In some cases, yet, loss of AV synchrony because of a marked prolongation of the PR interval may cause important hemodynamic alterations, with subsequent symptoms of heart failure. Indeed, AV synchrony is crucial when atrial systole, the "atrial kick", contributes in a major way to left ventricular filling, as in case of reduced left ventricular compliance because of aging or concomitant structural heart disease.

Case presentation

We performed a trans-septal left atrium catheterization aimed at evaluating the entity of a mitral valve stenosis in a 72-year-old woman with a marked first-degree AV block, a known moderate aortic stenosis and NYHA class III symptoms of functional deterioration. We occurred in a deep alteration in cardiac hemodynamics consisting in an end-diastolic ventriculo-atrial gradient without any evidence of mitral stenosis. The patient had a substantial improvement in echocardiographic parameters and in her symptoms of heart failure after permanent pacemaker implantation with physiological AV delay.

Conclusion

We conclude that if a marked first degree AV block is associated to instrumental signs or symptoms of heart failure, the restoration of an optimal AV synchrony, achieved with dual-chamber pacing, may represent a reasonable therapeutic option leading to a consequent clinical improvement.     

Pregnancy in women with prosthetic heart valves

Pregnancy in women with mechanical valve prostheses has a high maternal complication rate including valve thrombosis and death. Coumarin derivatives are relatively safe for the mother with a lower incidence of valve thrombosis than un-fractionated and low-molecular-weight heparin, but carry the risk of embryopathy, which is probably dose-dependent. The different anticoagulation regimens are discussed in this review. When valve thrombosis occurs during pregnancy, thrombolysis is the preferable therapeutic option. Bioprostheses have a more favourable pregnancy outcome than mechanical prostheses but due to the high re-operation rate in young women they do not constitute the ideal alternative. When women with native valve stenosis need pre-pregnancy intervention, mitral balloon valvuloplasty is the best option in mitral stenosis, while the Ross operation or homograft implantation may be the preferable surgical regimen in aortic stenosis. (Neth Heart J 2008;16:406-11.)     

浅谈二尖瓣交界分离术中监护和输液与复苏的关系

本文通过116例二尖瓣决窄分离术中监护和输液,从中体会到术中监护是心脏手术成功必不可少的条件。只有做好术中监护,才能及时了解病情发展,正确指导复苏和输液,提高手术的安全系数。