多普勒超声心动图对原因不明心脏收缩期杂音的诊断价值

目的　探讨多普勒超声心动图技术判定原因不明心脏收缩期杂音性质的价值。方法　选择门诊初诊的原因不明心脏杂音的患者 16 0例 ,年龄 14～ 86 (5 6± 2 4)岁 ,分析比较心内科医师进行临床心脏检查 (无临床病史、心电图及 X线资料参考 )和超声心动图检查判定心脏杂音性质的准确性。结果　超声心动诊断功能性杂音 38例 ,器质性杂音 12 2例 ,以主动脉和二尖瓣复合病变最常见 ;其中主动脉瓣狭窄 (AS) 38例 ,主动脉瓣反流 (AR) 32例 ,二尖瓣反流 (MR) 4 5例 ,三尖瓣反流 (TR) 2 8例 ,二尖瓣脱垂 (MVP) 15例 ,室间隔缺损 (VSD) 12例 ,另外有 19例患者可记录到收缩晚期室内峰值压差。临床心脏检查确定功能性杂音、AS、AR、MR、TR、MVP、VSD及室内峰值压差的敏感性依次为 6 6 %、73%、2 2 %、72 %、6 0 %、5 6 %、98%及 2 1% ,与孤立性瓣膜病变比较 ,复合瓣膜病变时临床诊断的敏感性最差 (P<0 .0 0 1)。有 16例临床及超声心动图心脏检查不符。结论　临床心脏检查确定杂音性质有局限性 ,特别是在一个以上部位瓣膜病变时 ,因此对原因不明的心脏收缩期杂音常规进行超声心动图检查则可明确诊断     

Etiology and diagnosis of systolic murmurs in adults

Background

It is unknown whether echocardiography can provide insights into the origin of systolic murmurs and the modern value of bedside cardiovascular diagnosis.

Methods

The author examined 376 inpatients and compared their physical findings to transthoracic echocardiography, exploring the associations between echocardiography and systolic murmurs and investigating the diagnostic accuracy of physical examination for pathologic murmurs.

Results

Four echocardiographic variables predict the presence of systolic murmurs: peak aortic velocity (P <.001); mitral regurgitation severity (P <.001); mitral valve E-point velocity (P = .09); and absence of pericardial effusion (P = .09). When diagnosing murmurs, the most helpful finding is its distribution on the chest wall with respect to the 3^rd left parasternal space, a landmark that distinguishes murmurs into 6 patterns. The “apical-base” pattern indicates increased aortic velocity (likelihood ratio [LR] 9.7; 95% confidence interval [CI]; 6.7-14): a delayed carotid upstroke (LR 6.8; 95% CI; 4.0-11.5); absent S2 (LR 12.7; 95% CI; 5.3-30.4); and humming quality to the murmur (LR 8.5; 95% CI; 4.3-16.5) further increase the probability of aortic valve disease. The “broad apical” murmur pattern suggests significant mitral regurgitation (LR 6.8; 95% CI; 3.9-11.9); and the “left lower sternal” murmur pattern indicates significant tricuspid regurgitation (LR 8.4; 95% CI; 3.5-20.3): additional bedside observations refine these diagnoses. Nonetheless, this study shows that some classic physical findings are no longer accurate, that physical examination cannot reliably distinguish severe aortic stenosis from less severe stenosis, and that classic physical findings, despite having proven value, are absent in many patients with significant cardiac lesions.

Conclusions

In the diagnosis of systolic murmurs, physical examination has limitations but also unappreciated value. A simple system using onomatopoeia and classifying systolic murmurs into 1 of 6 patterns is diagnostically helpful.     

Evaluation of systolic murmurs by Doppler ultrasonography

Non-invasive continuous and pulsed wave Doppler ultrasonography was performed in 102 consecutive patients with clinically ill defined systolic murmurs to differentiate between flow murmurs, mitral regurgitation, aortic stenosis, and ventricular septal defect, as well as to assess the severity of aortic stenosis. Diagnoses with the Doppler method were based on velocity, direction, and duration of flow signals and were subsequently verified by cardiac catheterisation in all patients. Multiple evaluations were made in 31 patients. Sensitivity and specificity were 0.87 and 0.77 in mitral regurgitation, 0.9 and 1.0 in aortic stenosis, and 1.0 and 1.0 in ventricular septal defect. In 67 patients the estimation of severity of aortic stenosis using the Doppler technique to calculate aortic pressure gradients from maximum flow velocity was significantly correlated with that determined at catheterisation. It is concluded that Doppler ultrasonography is a highly useful technique for the non-invasive evaluation of clinically ill defined systolic murmurs.     

The clinical significance of systolic murmurs in the elderly.

A group of 278 patients, over the age of 60 years, and representative of geriatric and general medical admissions to the District General Hospital in Banbury, Oxforshire, was studied to correlate the prevalence of systolic murmurs to age, sex, cardiac failure, ischaemic heart disease, dysrrhythmias, hypertension, peripherial vascular disease and anaemia. The object was to establish the clinical significance of these murmurs and test a postulate that they could not be dismissed as benign. Seventy-five per cent of the murmurs were judged to be aortic and 12 per cent mitral in origin. The prevalence of systolic murmurs increased with age from 32 per cent at 60-64 years to 57 per cent over 85 years, and was greater in females (44 per cent) than in males (34 per cent). The presence of systolic murmurs was related to the presence of cardiac failure, ischaemic heart disease, dysrrhythmias, hypertension, peripheral vascular disease and anemia. Only 8 per cent of patients with systolic murmurs had none of the above-mentioned six cardiovascular abnormalities compared with 36 per cent of patients without such a murmur, while multiple cardiovascular abnormalities were also commoner in the former group. The mortality rate in hospital was similar for patients with or without a systolic murmur.     

Pacemaker catheter induced systolic murmurs in two patients

Although extracardiac sounds secondary to cardiac pacing have been well known, the murmurs originating in the heart after permanent pacemaker implantation and then disappearance after exchanging a temporary to permanent lead have rarely been reported. In this paper, two patients revealing a musical systolic murmur after placement of a transvenous endocardial pacemaker in the absence of any complications were documented. Case 1: A 43-year-old man with episodes of dizziness and brady-tachycardiac atrial fibrillation. Immediately after the implantation of a temporary transvenous right ventricular pacemaker, a high-pitched systolic musical murmur was heard at the lower left sternal border. No murmur was however gullible after a permanent pacemaker implantation in this case. Case 2 was a 83-year-old female with coronary heart disease associated with sick sinus syndrome to whom a permanent transvenous right ventricular pacemaker was inserted. A musical systolic murmur occurring immediately after the procedure was best audible at the apex. Although numerous papers concerning the mechanisms of these cardiac murmurs have been reported without reaching conclusive explanations, our data based on two cases examined with Doppler echocardiography did not support the idea of tricuspid regurgitation as one of causative factors. In the first case, this murmur appeared only a temporary pacing was performed and disappeared after implantation of a permanent pacemaker lead. On the contrary, however, the 2nd case revealed after the implantation of the permanent pacemaker with a relatively rigid bipolar lead. It is concluded that these murmurs might be produced by vibrations caused by the pacing catheters and physical properties could be related the mechanism of this phenomenon.     

Degenerative calcific valvular disease and systolic murmurs in the elderly

By use of echocardiographic and radiologic imaging, a prospective study was made of 98 elderly men, 65 to 102 years old, to define degenerative calcific valvular disease (DCVD)--its prevalence, morphologic features, functional significance, and relationship to systolic murmurs in the elderly. DCVD was diagnosed in 74 per cent of the group and murmurs were detected in 55 per cent, the incidences increasing with age. Fibrotic and calcific change of the aortic valve was the most common abnormality, occurring alone or together with alteration of the mitral valve. The murmurs were characteristically early systolic, of low intensity and medium pitch, and heard at more than one area. Of the group with valve degeneration, only 7 per cent was judged to be functionally significant and no more than moderate. It was concluded that DCVD is the cause of most systolic murmurs in the elderly and is usually hemodynamically unimportant. Echocardiographic criteria are important in identifying those subjects with possibly significant valvular dysfunction requiring invasive study.