Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ventricular Outflow Obstruction”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,081 records · Page 60Linked to original sources

Systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy: an in vitro pulsatile flow study.

Hypertrophic cardiomyopathy, or HCM, is a relatively common disease which results in the hospitalization of more than 13,000 patients every year. It is characterized by a thickening of the interventricular septum and by systolic anterior motion, or SAM, of the mitral valve, which occurs when the distal tip of the mitral leaflets contacts the hypertrophied septum during systole and obstructs the left ventricular outflow tract. Using an in vitro pulsatile flow model of the left ventricle, the objective of the study was to investigate the relationship between the ventricular flow field and the mechanism of SAM and to specifically address the hypothesis that papillary muscle displacement can alter left ventricular flow patterns and create drag forces that can initiate SAM. Flow visualization revealed the presence in the ventricle of a large organized recirculation region throughout diastole. Besides maintaining the mitral leaflets close to the posterior wall, normally positioned papillary muscles also caused the diastolic vortex to help the mitral valve close near the posterior wall while simultaneously prepositioning the upcoming systolic outflow stream close to the septum, thereby minimizing the flow forces acting on the mitral valve. In contrast, the anterior displacement of the papillary muscles moves the entire mitral apparatus into the outflow tract. It also reverses the direction of the recirculating diastolic flows: The diastolic vortex now promotes the initiation of SAM by displacing the closing mitral leaflets anteriorly and by positioning the systolic outflow stream close to the posterior wall. These events lead to the creation of form drag forces as the systolic flow impacts the posterior side of the mitral leaflets, initiating SAM.

Cardiac Output↗

[2D and Doppler echocardiography after atrial switch operation for transposition of great arteries; a review].

Introduction of the atrial baffle procedure (Mustard, Senning) more than 30 years ago has dramatically improved the prognosis of patients with transposition of the great arteries. However, a range of late complications can occur even in clinically asymptomatic patients including: superior and inferior limb obstruction, pulmonary venous obstruction, residual baffle-leakage, left ventricular outflow tract obstruction, tricuspid valve regurgitation, right ventricular dysfunction and postoperative dysrhythmia. As an increasing number of patients has reached adulthood an accurate noninvasive technique is needed for routine follow-up studies. In most patients transthoracic two-dimensional (2D) and Doppler echocardiography allows a complete investigation of postoperative hemodynamic abnormalities -- in particular assessment of atrial baffle function. In adult patients with restricted echo-windows transoesophageal echocardiography may provide a more detailed assessment of atrial baffle morphology and function; TEE seems to be superior compared to angiography and magnetic resonance imaging. Furthermore TEE is a reliable guiding and monitoring technique during interventional cardiac catheterization procedures such as balloon dilatation or stent implantation and allows further surveillance. Even if compared to other noninvasive diagnostic procedures, 2D and Doppler echocardiography (transthoracic/transoesophageal) are still the most important and accurate diagnostic methods for routine investigation of the postoperative anatomy and potential late complications in patients who underwent an atrial baffle procedure.

Echocardiography↗

The results of a surgical program for interrupted aortic arch.

Seventy-one patients with interrupted arch entered the Boston Children's Hospital between Jan. 1, 1974, and Jan. 1, 1987, of whom 63 underwent an operation. Type B was the most prevalent form of interrupted arch, and ventricular septal defect alone was the commonest coexisting cardiac anomaly. Among the 63, the 30-day and the 1-, 5-, and 10-year survival rates were 61%, 52%, 48%, and 47%, respectively. The mortality rate declined strikingly during the experience, and by multivariate analysis in patients with coexisting ventricular septal defect operated on in 1986, the probability of death within 2 weeks of repair was only 7%. Also, preoperative therapy became progressively more intense and more prolonged. The complication of left ventricular outflow tract obstruction developed in eight of the 33 patients undergoing repair of interrupted arch and of isolated ventricular septal defect. The time-related freedom from this complication was 97%, 78%, and 58% at 1 month, 1 year, and 3 years, respectively. Seven of the eight patients underwent a surgical procedure directed against the left ventricular outflow tract obstruction, and all have survived. Recurrent or persistent aortic arch obstruction became evident after repair in 15 patients and appeared more frequently and earlier after direct anastomosis than after tube graft repair. All patients had either reoperation or balloon dilation, but all were alive at follow-up. Most surviving patients are active and without symptoms. Inferences: An aggressive surgical program can result in survival and a good clinical state for at least 10 years after birth of over 40% of patients born with interrupted arch. Multiple anatomic bases account for the development of left ventricular outflow tract obstruction in about 50% of the patients undergoing repair of interrupted arch with coexisting ventricular septal defect. Repair by direct anastomosis combined with repair of the coexisting defect whenever possible is optimal therapy.

Aorta, Thoracic↗

Surgical management of the straddling mitral valve in the biventricular heart.

BACKGROUND: The straddling mitral valve in the biventricular heart is a rare condition that may complicate biventricular repair. METHODS: Treatment and outcomes in 5 consecutive patients who underwent primary repair between 1992 and 1997 were reviewed. Their ages at repair ranged from 2 months to 8 years. Three patients had a double-outlet right ventricle with a subaortic (n = 2) or subpulmonary (n = 1) ventricular septal defect. Two patients had transposition of the great arteries (S,D,D), a ventricular septal defect, and left ventricular outflow tract obstruction. The attachments of the papillary muscles of the straddling mitral valves were located on the right ventricular aspect of the ventricular septum. Four patients underwent baffle partitioning of the ventricular cavity. The baffle suture line was used to secure the chordae tendineae crossing the ventricular septal defect, or was intentionally omitted at the papillary muscle. The right ventricular outflow tract was reconstructed with patch augmentation, an extracardiac conduit, or an arterial switch operation. One patient with transposition who had a giant papillary muscle to the straddling mitral valve associated with abnormal insertion of the tricuspid valve on the conal septum underwent univentricular repair. RESULTS: There were no early or late postoperative deaths. There was no mitral valve dysfunction, left ventricular outflow tract obstruction, or heart block in the 4 patients who underwent biventricular repair. CONCLUSIONS: Although there are several exceptional situations in which ventricular partitioning may result in early and late complications, a straddling mitral valve does not preclude biventricular repair.

Cardiac Catheterization↗

[Peripheral vascular reflexes in obstructions of the left ventricular outflow tract. Experimental study].

UNLABELLED: The aim of this work is to analyze the vascular tone behaviour of the muscular arteries in relation to the reflexes generated during aortic root obstruction when spontaneous heart rate is permitted and also with induced tachycardia. An experimental model used involved anaesthetized and intubated dogs in which a resistance vessel (gracilis muscle artery) was isolated, while innervation and venous backflow remained intact. Moderate (54.4 +/- 23.2 mmHg of mean increase in left ventricular pressure) and severe (240.1 +/- 92.5 mmHg) aortic obstructions for 30 s were provoked during spontaneous heart rate (n = 15) and during ventricular overdriving (n = 13) at 200, 250 and 300 bpm for 30 s. Ventricular overdriving at 200, 250, 300 and 400 bpm for 30 s without aortic root obstruction was induced in 20 dogs. Ventricular overdriving in intact hearts produced an initial decrease in the isolated muscular artery pressure of 12.0 +/- 7.2 mmHg (p < 0.01), 9.5 +/- 5.7 mmHg (p < 0.001), 13.6 +/- 8.6 mmHg (p < 0.001) and 14.3 +/- 8.7 mmHg (p < 0.01) at 200, 250, 300 and 400 bpm respectively followed by a recovery, so that at the end of overdriving (30 s), exceeded basal values in 11.9 +/- 10.0 mmHg (p < 0.05), 21.1 +/- 12.4 mmHg (p < 0.001), 21.9 +/- 10.4 mmHg (p < 0.001) and 36.1 +/- 21.3 mmHg (p < 0.001) for each overdriving rate respectively. Aortic obstruction during spontaneous heart rate produced and initial decrease in the isolated muscular artery pressure of 12.0 +/- 7.3 mmHg (p < 0.01), when the aortic obstruction were moderate, and 31.4 +/- 15.7 mmHg (p < 0.01) when the obstructions were severe, followed by a recovery of its basal values at the end of the obstruction time. Ventricular overdriving with aortic root obstruction did not produced significant changes in the isolated muscular artery pressure except in the highest rates of overdriving, that produced an increase of isolated muscular artery pressure of 23.9 +/- 16.2 mmHg (p < 0.01). IN CONCLUSION: ventricular overdriving-induced hypotension in intact hearts produces an isolated muscular artery response with clear vasoconstrictor predominance. Aortic obstruction-induced hypotension does not produce a vasoconstrictor response in the isolated muscular artery but rather an initial vasodilation response which does not revert to vasoconstriction at any point during the hypotensive process. Overdriving was not capable of inducing a peripheral vasoconstriction in presence of aortic root obstruction except in the highest rates of overdriving.

Animals↗

The case for surgery in obstructive hypertrophic cardiomyopathy.

Relief of left ventricular (LV) outflow obstruction in patients with hypertrophic cardiomyopathy (HCM) and disabling symptoms refractory to maximum medical management has historically been a surgical problem. Surgical septal myectomy permanently abolishes systolic anterior motion of the mitral valve and mitral regurgitation, while normalizing LV pressures and wall stress. Also, these salutary goals are achieved without encumbering patients with post-procedural devices (e.g., pacemakers or defibrillators) or creating potentially arrhythmogenic substrates, as may occur with alcohol septal ablation. Procedural morbidity and mortality risk with myectomy is similar to, and in some institutions less than those for alcohol septal ablation. Over four decades, reports from numerous centers worldwide have consistently and unequivocably documented the benefits of surgery on hemodynamic and functional state, restoring normal and acceptable quality of life to patients of all ages by largely reversing the complications of heart failure. Long-term survival after myectomy is similar to that of the general population and superior to non-operated patients with obstruction. The LV outflow tract morphology in HCM is heterogeneous and not uncommonly includes congenital anomalies of the mitral valve apparatus for which the surgeon has the flexibility to adapt the repair, often employing an extended myectomy. In the current atmosphere of increasing and perhaps excessive enthusiasm for newer catheter-based interventions, it is a critical time to promote and re-emphasize that surgery is the time-honored (and presently the most effective) treatment strategy for relieving heart failure-related disability resulting from dynamic LV outflow obstruction in HCM, and is the primary treatment option for this subgroup of severely symptomatic drug-refractory patients.

Cardiomyopathy, Hypertrophic↗

Morphology of left ventricular outflow tract structures in patients with subaortic stenosis and a ventricular septal defect.

OBJECTIVE: To compare the incidence and prognosis of subaortic stenosis associated with a ventricular septal defect and to define the morphological basis of subaortic stenosis. DESIGN: Presentation and follow up data on 202 patients with subaortic stenosis seen at the Royal Liverpool Children's Hospital between 1 January 1960 and 31 December 1991 were reviewed. Survivors were traced to assess their current clinical state. Necropsy specimens of 291 patients with lesions associated with subaortic stenosis were also examined. RESULTS: In the clinical study; 65 (32.1%) of the 202 patients with subaortic stenosis had a ventricular septal defect (excluding an atrioventricular septal defect). 32 of these patients had a short segment (fibromuscular) subaortic stenosis. 33 had subaortic stenosis produced by deviation of muscular components of the outflow tracts. In 17 patients (51.5%) this was caused by posterior deviation or extension of structures into the left ventricular outflow tract, resulting in obstruction above the ventricular septal defect. In the other 16 patients (48.5%) there was over-riding of the aorta with concordant ventriculoarterial connections, (without compromise to right ventricular outflow) producing subaortic stenosis below the ventricular septal defect. Additional fibrous obstruction occurred in 39% of the patients with deviated structures. The age at presentation was lower (P < 0.01) in patients with deviated structures (median (range) 0.4 (0 to 9.2) months) than in those with short segment obstruction (median (range) 4.2 (0 to 84.9) months). The incidence of aortic arch obstruction was higher (P < 0.002) in patients with deviated structures than in those with short segment obstruction (38%). In the morphological study 35 pathological specimens showed obstructive muscular structures in the left ventricular outflow tract either above or below the ventricular septal defect. 16 had either posterior deviation of the outlet septum or extension of the right ventriculoinfundibular fold, or both of these together into the left ventricle. 19 had anterior deviation of the outlet septum into the right ventricle with overriding of the aorta (without compromise to right ventricular outflow). The earliest age at which additional fibrous obstruction was seen was 9 months. The aortic valve circumference was small in 18% of specimens. FOLLOW UP: The median (range) duration of follow up in survivors from the clinical study was 6.6 (1 to 25.7) years. 16 patients with deviated musculature (49%) and 16 with short segment fibromuscular stenosis (50%) underwent operation for subaortic stenosis. Patients with deviated structures were younger at operation than those with short segment stenosis (P < 0.005). Patients with posterior deviation or extension of structures into the left ventricular outflow tract underwent operation for subaortic stenosis more frequently (P < 0.05) than those with anterior deviation of the outlet septum and aortic override. The ventricular septal defect required surgical closure more frequently (P < 0.005) in patients with deviation (93.9%) than in those with short segment obstruction (21.9%). There was no significant difference in the mortality between patients with deviation (27%) and those with short segment obstruction (12%). CONCLUSIONS: 32% of patients in the clinical study with subaortic stenosis had a ventricular septal defect. Only 51% of these had obstructive and deviated muscular structures in the left ventricular outflow tract. These patients had a significantly higher incidence of aortic arch obstruction and required surgery for subaortic stenosis at a younger age than those with short segment obstruction. The ventricular septal defect also required surgical closure more frequently in those patients with deviation. The morphological study defined the two sites of obstruction. The presence or absence and type of deviation should be clearly defined in all patients with a ventricular septal defect,

Aortic Stenosis, Subvalvular↗

Hypertrophic cardiomyopathy. Disappearance of auscultatory, carotid pulse, and echocardiographic manifestations of obstruction following myocardial infarction.

Three patients with echocardiographically documented asymmetric septal hypertrophy and findings compatible with dynamic left ventricular outflow tract obstruction suffered acute myocardial infarction in regions remote from the interventricular septum. Following infarction, echocardiographic signs of dynamic left ventricular outflow tract obstruction were no longer apparent. No resting gradient was documented in either of the two patients undergoing cardiac catheterization following myocardial infarction. Valsalva's maneuver resulted, however, in a gradient of 20 mm Hg in one patient. It appears that myocardial infarction may cause loss of or marked lessening of dynamic left ventricular outflow tract obstruction, even when the infarction involves areas other than the septum.

Aged↗

Hydatid cyst of the interventricular septum causing obstruction of the right ventricular outflow tract: cross-sectional echocardiographic, angiographic and pathological findings.

Cardiac echinococcal cysts rarely involve the interventricular septum; when they do, they cause symptoms mainly related to the compression of the atrio-ventricular conduction pathways. Mild obstruction of the right ventricular outflow tract has also been described in some cases. In the case reported here, an unusual large hydatid cyst located in the interventricular septum produced a marked, symptomatic obstruction of the right ventricular outflow tract (more than 100 mmHg gradient). Surgical resection of the cyst was complicated by a 'stone heart' syndrome, probably because of a severely affected right ventricle. Cross-sectional echocardiography gave the exact site and aetiology of the mass. On the basis of these non-invasive findings, early surgery should be performed on asymptomatic patients to reduce the risk of life-threatening evolutions.

Adult↗

Long-term follow-up of operated congenital heart disease.

The long-term follow-up status of patients operated upon for the more common forms of congenital heart disease is reviewed. Among patients with large left-to-right shunts the long-term prognosis for those with ASD and VSD is generally excellent. With rare exceptions, these patients can look forward to a normal adulthood. Residual atrioventricular valve disease complicates the long-term course of infants and children operated upon for atrioventricular canal, but nevertheless, most patients have remained stable for many years. Among patients after relief of right ventricular outflow tract obstruction, excellent documentation of long-term stability has been reported for children with valvular pulmonary stenosis, and most patients with tetralogy of Fallot appear to tolerate residual right ventricular outflow stenosis and insufficiency without serious complications. Dysrrhythmias occur, but severe sequelae are rare. The prognosis for survivors of pulmonary atresia with VSD is more guarded. Conduit longevity appears to be the most important concern, and long-term studies indicate that xenografts rarely last beyond a decade. The modern types of homografts cannot yet be evaluated on a long-term basis. For patients with pulmonary atresia and intact ventricular septum, there are a number of long-term survivors, but most have chronic right heart dysfunction with only a rare, outstanding result. The long-term outlook for patients with left ventricular outflow obstruction is guarded. Most patients after repair of aortic stenosis have residual aortic stenosis and/or insufficiency. Postaortic valvotomy adults tend to be symptom-free, despite residual disease, but almost certainly late management will be required.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

[Assessment with magnetic resonance tomography of anatomy and ventricular function after Mustard correction of transposition of the great arteries].

In order to evaluate postoperative sequelae and ventricular function after Mustard-operation in patients with transposition of the great arteries (TGA), 30 patients were assessed by magnetic resonance imaging in EKG-triggered spin-echo (SE) and gradient-echo (GE) technique. Twenty-three patients, aged 4.7 to 15.8 years, had transposition of the great arteries with intact ventricular septum with or without left-ventricular outflow tract obstruction (TGA+IVS +/- SPS). Seven patients aged 9.5 to 21.7 years had transposition of the great arteries with ventricular septal defect (TGA+VSD). Five patients showed a residual baffle leak, one had a pulmonary venous obstruction, five an obstruction at the caval veins, 13 a left-ventricular outflow tract obstruction, and 14 a tricuspid regurgitation. Right-ventricular enddiastolic volume in patients with TGA+VSD (77.0 +/- 25.5 ml/m2) was significantly higher than in patients with TGA+IVS +/- SPS (61.2 +/- 12.0 ml/m2). In TGA+VSD right-ventricular ejection fraction (47.6 +/- 13.0%) was significantly lower than in patients with TGA+IVS +/- SPS (56.7 +/- 10.7%). The ratio of muscle masses of right to left ventricle was 1.8:1 in patients with TGA+IVS +/- SPS and 2.5:1 in patients with TGA+VSD. In conclusion, after Mustard-operation in patients with transposition of the great arteries (TGA) magnetic resonance imaging provides a comprehensive and noninvasive assessment of postoperative sequelae, residuae, and ventricular function and will, therefore, become the method of choice for postoperative evaluation.

Child, Preschool↗

Asymmetric septal hypertrophy complicated by dynamic left ventricular obstruction after intra-aortic balloon counterpulsation placement in the setting of anterior myocardial infarction.

We report the case of a 74-year-old patient admitted for acute anterior myocardial infarction and treated by intravenous thrombolysis. Because of hemodynamic instability, an intra-aortic balloon pump (IABP) was inserted. However, the patient's systolic blood pressure deteriorated early after IABP placement. Echocardiography revealed a dynamic left ventricular outflow tract obstruction occurring only during assisted ventricular systoles. Interruption of counterpulsation allowed complete resolution of the dynamic obstruction and improvement of hemodynamic status.

Aged↗

Double outlet right ventricle: opinions regarding management.

In the current era of superb surgical results for congenital heart disease, several management options are available for patients born with double outlet right ventricle (DORV). The surgical repair of DORV is tailored to address the variety of abnormalities associated with this lesion. The treatment strategies are dependent upon the anatomy and relationship of the ventricular septal defect (VSD) and the great arteries. For patients with subaortic or doubly committed VSDs, without right ventricular outflow tract obstruction, the usual repair is an intraventricular tunnel from the VSD to the aorta. If right ventricular outflow tract obstruction exists, then augmentation of the right ventricular outflow tract or conduit placement from the right ventricle to the pulmonary artery is necessary. For the "Taussig-Bing anomaly" (subpulmonary VSD) an arterial switch operation is indicated with tunneling of the VSD to the neoaorta. For patients with a remote VSD, complex atrioventricular valve abnormalities, or unbalanced ventricles, a staged palliative approach is warranted. This approach will result in the patient having "single ventricle" physiology, and "Fontan anatomy" after the staging surgeries. Outcomes are determined by the surgery performed. Patients who require conduit placement from right ventricle to pulmonary artery will need subsequent surgery for replacement of the conduit. Complex intraventricular tunnels are at risk for developing subaortic obstruction. Patients who had arterial switch operations have thus far had excellent results. However, these patients may be at risk for development of neoaortic valve regurgitation requiring subsequent reoperation. Complex biventricular intracardiac repairs have been associated with a higher risk of reoperation. In the past 10 to 15 years, patients undergoing Fontan operations have had improved early and late survival. However, long-term problems after the Fontan operation include arrhythmia and development of protein-losing enteropathy.

Journal Article↗