SEARCH · Search PubMed
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.
Two infants with chaotic atrial tachycardia diagnosed at birth and at 11 weeks of life, were treated successfully with oral flecainide. Both patients were in heart failure at initiation of therapy. Six months and 17 months later, respectively, they have had no recurrence of chaotic atrial tachycardia, left ventricular function returned to normal and therapy was stopped in both.
The clinical situation of heterogeneous cardioplegia was simulated in a canine model by temporary ligation of the circumflex coronary artery during a three-hour interval of cardioplegic arrest. Nifedipine and lidoflazine, administered prior to aortic clamping, were evaluated as adjuncts to cold (2 degrees C) crystalloid cardioplegia. Assessment was made of regional function (sonomicrometer systolic shortening) and of global function by measuring left atrial (LA) pressure at constant cardiac output (CO), aortic pressure, and heart rate, and by measuring stroke work at constant LA pressure, aortic pressure, and heart rate. Among 14 control dogs, only 7 could achieve a CO of 5 liters per minute following cardioplegic arrest. Left anterior descending coronary arterial systolic shortening recovered to only 86% of prearrest values (p less than 0.05), circumflex coronary arterial systolic shortening recovered only 28% (p less than 0.01), stroke work recovered 59% (p less than 0.01), and LA pressure was 6.7 mm Hg higher (p less than 0.01) than prior to cardioplegic arrest. Lidoflazine provided no statistically significant benefit in these animals (N = 4). However, dogs given nifedipine (N = 6) had very little change in left anterior descending coronary arterial systolic shortening (99% recovery), stroke work (93% recovery), and LA pressure (delta = 0.4 mm Hg). None of these changes was statistically significant. There was some deterioration in circumflex coronary arterial systolic shortening (56% recovery; p less than 0.05). All 6 dogs given nifedipine achieved a CO of 5 L/min following cardioplegic arrest. Clinical cardioplegia is typically heterogeneous cardioplegia. Calcium-channel blockade appears to be useful in this situation.
OBJECTIVES: We compared the effects of five pharmacologic regimens on the circadian rhythm and exercise-induced changes of ventricular rate (VR) in patients with chronic atrial fibrillation (CAF). BACKGROUND: Systematic comparison of standardized drug regimens on 24 h VR control in CAF have not been reported. METHODS: In 12 patients (11 male, 69+/-6 yr) with CAF, the effects on VR by 5 standardized daily regimens: 1) 0.25 mg digoxin, 2) 240 mg diltiazem-CD, 3) 50 mg atenolol, 4) 0.25 mg digoxin + 240 mg diltiazem-CD, and 5) 0.25 mg digoxin + 50 mg atenolol; were studied after 2 week treatment assigned in random order. The VR data were analyzed by ANOVA with repeated measures. The circadian phase differences were evaluated by cosinor analysis. RESULTS: The 24-h mean (+/-SD) values of VR (bpm) were - digoxin: 78.9 +/- 16.3, diltiazem: 80.0+/-15.5, atenolol: 75.9+/-11.7, digoxin + diltiazem: 67.3+/-14.1 and digoxin + atenolol: 65.0+/-9.4. Circadian patterns were significant in each treatment group (p < 0.001). The VR on digoxin + atenolol was significantly lower than that on digoxin (p < 0.0001), diltiazem (p < 0.0002) and atenolol (p < 0.001). The time of peak VR on Holter was significantly delayed with regimens 3 and 5 which included atenolol (p < 0.03). During exercise, digoxin and digoxin + atenolol treatments resulted in the highest and lowest mean VR respectively. The exercise Time-VR plots of all groups were nearly parallel (p = ns). The exercise duration was similar in all treatment groups (p = ns). CONCLUSIONS: This study indicates that digoxin and diltiazem, as single agents at the doses tested, are least effective for controlling ventricular rate in atrial fibrillation during daily activity. Digoxin + atenolol produced the most effective rate control reflecting a synergistic effect on the AV node. The data provides a basis for testing the effects of chronic suppression of diurnal fluctuations of VR on left atrial and ventricular function in CAF.
Abnormal pulmonary venous flow velocity patterns are present in multiple cardiac disease states, but the determinants of pulmonary venous flow velocity have not been fully elucidated. To determine the relative importance of several proposed factors that could influence pulmonary venous flow, anatomic, hemodynamic, and Doppler mitral and pulmonary venous flow velocity data were compared in 50 consecutive patients undergoing cardiac catheterization for clinical reasons. Pulmonary venous diastolic flow velocity was most strongly related to left ventricular isovolumetric relaxation time (r = -0.59), left ventricular end-diastolic pressure (LVEDP, r = 0.50), left atrial minimum volume (r = 0.50), mitral deceleration time (r = -0.50), and early diastolic mitral flow velocity (r = 0.45). Pulmonary venous systolic flow velocity related best with left atrial minimum volume (r = -0.45) and left atrial ejection fraction (r = 0.44). Pulmonary venous systolic flow velocity integral also showed the strongest relation with left atrial minimum volume (r = -0.48). Relations between pulmonary venous flow velocity and velocity time integrals and other variables were sometimes significantly different, apparently caused in part to differences in heart rate. These results suggest that pulmonary venous diastolic flow velocity is influenced by the same factors that influence early left ventricular diastolic filling; pulmonary venous systolic flow velocity relates best to left atrial volume and atrial ejection fraction and does not relate to left ventricular ejection fraction. Future studies analyzing pulmonary venous flow velocity variables should include data on both peak velocities and velocity time integrals as well as left atrial size and function.
OBJECTIVE: To determine the efficacy of anatomic biventricular repair by a combination of intraatrial and intraventricular re-routing in patients with isomerism of the left atrial appendages. METHODS: Anatomic biventricular repair by means of combined intraratrial and intraventricular re-routing was achieved in 5 of the 63 patients with left isomerism in whom we attempted a definitive surgical procedure. The inferior caval vein was interrupted in 3. The Mustard procedure was chosen for intraatrial redirection of blood in 4, and the Senning procedure in the other. Intraventricular re-routing was carried out via a right ventriculotomy in all patients, using an external conduit to reconstruct the morphologically right ventricular outflow tract. RESULTS: One patient died one month after the procedure because of low cardiac output and bronchial bleeding. Obstruction across the superior caval venous channel occurred after the Senning procedure in this particular patient, related to the interrupted inferior caval vein draining via the azygous vein. The other 4 patients are currently doing well. Postoperative catheterization showed excellent cardiac performance, with no obstruction across the venous channels or the ventricular outflow tracts in these 4. No episode of significant arrhythmia has been noted, all patients having a regular atrial rhythm, although the P wave vector was unusual in each patient. Reoperation has been needed thus far in one patient, 128 months after the initial repair, because of obstruction of the external conduit. CONCLUSION: With precise recognition of the morphologic features, a combination of intraatrial and intraventricular re-routing can successfully be established in patients with isomeric left atrial appendages, with functional results in the intermediate term being reasonable.
The acute effect of failed attempts of cardioversion on left atrial (LA) and left atrial appendage (LAA) functions are generally considered benign and no adverse effects have been reported. We report on a subject who had rapid formation of a fresh, mobile thrombus in the LAA despite unsuccessful cardioversion and therapeutic anticoagulation.
Stress hormones, tissue-plasminogen activator (t-PA) antigen, left-ventricular diastolic function and mood immediately before and after listening to three different kinds of music (a waltz by J. Strauss, a piece of modern classic by H. W. Henze, and meditative music by R. Shankar) were measured in 20 healthy persons (10 women, 10 men; mean age 25 [20-33] years) and 20 hypertensives (8 women, 12 men; mean age 57.5 [25-72] years). To recognise haemodynamic effects, mitral flow by Doppler ultrasound was used as a measure of left-ventricular diastolic function. Atrial filling pressure (AFF) was calculated from the flow integral (VTI) of the early E and the late A waves. The Zerssen scale was used to estimate the immediate mood of the subjects. In hypertensives the levels of cortisol (74 vs 78 ng/ml; P < 0.05) and t-PA antigen (4.3 vs 4.5 ng/ml; P < 0.05) were lower after than before the Strauss waltz. The muscle by Henze lowered the concentrations of cortisol (70 vs 84 ng/ml; P < 0.05), noradrenaline (203 vs 224 ng/l; P < 0.05) and t-PA antigen (4.1 vs 4.6 ng/ml; P < 0.05). After listening to the piece by Shankar the concentrations of cortisol (71 vs 78 ng/ml; P < 0.05), adrenaline 14.5 vs 24.5 ng/ml; P < 0.05) and t-PA antigen (4.2 vs 4.3 ng/ml; P < 0.05) were lower. In healthy subjects AFF (29 vs 26%; P < 0.05) rose after the Strauss music, VTI-E fell (69 vs 73 mm; P < 0.05, while natriuretic peptide rose (63 vs 60 pg/ml; P < 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertrophic cardiomyopathy is a complex genetic condition with a heterogeneous clinical course. Some patients remain asymptomatic throughout life while others develop one or more of the adverse clinical consequences including symptoms of congestive heart failure with exertional dyspnea and functional disability (usually with preserved left ventricular systolic function), atrial fibrillation, or sudden cardiac death. Because of this heterogenicity in the clinical presentations, management of patients with hypertrophic cardiomyopathy includes a wide range of pharmacologic therapies as well as invasive approaches. In recent years, nonsurgical catheter-based treatment of hypertrophic cardiomyopathy has been increasingly used in the management of a subset of these patients. The authors present a case of percutaneous transluminal septal myocardial ablation in a patient with hypertrophic cardiomyopathy who was symptomatic despite maximal medical treatment.
The incidence of dual atrioventricular (AV) nodal physiology was evaluated in 22 patients (14 males, 8 females, age 52 +/- 18 years) undergoing electrophysiology studies for evaluation of ventricular tachycardia/nonsustained ventricular tachycardia (n = 11), supraventricular tachycardia (n = 5), and syncope (n = 6). Patients with AV node reentrant tachycardia were excluded. Thirteen patients had normal left ventricular function and nine patients (seven with coronary artery disease, two with dilated cardiomyopathy) had depressed left ventricular function. Single atrial extrastimuli (A2) were introduced after eight-beat drives at paced cycle lengths of 550 msec and 400 or 450 msec beginning at coupling intervals of 650 and 500 or 550 msec, respectively. The coupling interval was decreased at 10-msec intervals until AV node or atrial refractoriness. A second atrial extrastimulus (A3) was then added. A2 was fixed at 50 msec greater than the atrial or AV nodal refractory period. A3 was coupled to A2 at 650 and 500 or 550 msec and decremented as with single extrastimulation. Dual AV nodal physiology was defined by a 50-msec increase in A2H2 or A3H3 with a 10-msec decrement in the coupling interval or a discontinuous H1H2 versus A1A2 or H2H3 versus A2A3 curve. Using a single extrastimulus, 1 of 22 patients demonstrated dual AV nodal physiology. Using double extrastimuli, an additional four patients with dual AV nodal physiology were identified. The occurrence of dual AV nodal physiology determined using double extrastimuli is increased compared to using only a single extrastimulus (P = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
Primary cardiac tumours are quite rare and most of these tumours are benign. In this report, a patient presented with heart failure symptoms attributable to severe mitral valve stenosis. Echocardiography showed a dense left atrial mass causing functional mitral valve obstruction. The morphological and intraoperative presentation was highly suggestive of a myxoma but histopathological examination found a primary pedunculated cardiac angiosarcoma. The role of two dimensional and transoesophageal echocardiography in the assessment of cardiac masses and tumours is discussed.
OBJECTIVES: To investigate diagnostic routes, echocardiographic substrates, outcomes and prognostic factors in patients with isolated ventricular non-compaction (IVNC) identified by echocardiographic laboratories with referral from specialists and primary care physicians. PATIENTS AND DESIGN: Since 1991, all patients with suspected IVNC were flagged and followed up on dedicated databases. Patients were divided into symptom-based and non-symptom-based diagnostic subgroups. RESULTS: 65 eligible patients were followed up for 6-193 months (mean 46 (SD 44). In 53 (82%) patients, IVNC was associated with variable degrees of left ventricular (LV) dilatation and hypokinesia, and in the remaining 12 (18%) LV volumes were normal. Diagnosis was symptom based in 48 (74%) and non-symptom based in 17 (26%) (familial referral in 10). The non-symptom-based subgroup was characterised by younger age, lower prevalence of ECG abnormalities, better systolic function and lower left atrial size, whereas the extent of non-compaction was not different. No major cardiovascular events occurred in the non-symptom-based group, whereas 15 of 48 (31%) symptomatically diagnosed patients experienced cardiovascular death or heart transplantation (p = 0.01, Kaplan-Meier analysis). Independent predictors of cardiovascular death or heart transplantation were New York Heart Association class III-IV, sustained ventricular arrhythmias and left atrial size. CONCLUSIONS: IVNC is associated with a broad spectrum of clinical and pathophysiological findings, and the overall natural history and prognosis may be better than previously thought. Adult patients with incidental or familial discovery of IVNC have an encouraging outlook, whereas those who have symptoms of heart failure, a history of sustained ventricular tachycardia or an enlarged left atrium have an unstable course and more severe prognosis.
This study included 249 consecutive patients with suspected significant aortic valve stenosis. Using contemporary ultrasound equipment we reassessed the value of out-patient Doppler-derived maximum pressure gradients for the prediction of peak-to-peak pressure gradients measured later at heart catheterization. It was possible to record the pressure gradient in 97% of the patients by Doppler examination and in 86% at heart catheterization. There was a fair, statistically significant correlation between Doppler and invasive gradients (n = 201, r = 0.80, p < 0.05, SEE = 21 mm Hg), independent of coexistent aortic regurgitation, atrial fibrillation, left ventricular function, number of days between the examinations and other variables analysed. A Doppler gradient > 80 mm Hg was 98% (90-100%) predictive of critical aortic stenosis (gradient > 50 mm Hg as determined by heart catheterization). Similarly, a Doppler gradient of < or = 30 mm Hg was 98% (87-100%) predictive of non-critical stenosis. In the remaining patients (53% of the population) the Doppler gradient did not contribute decisively to clinical management.
Twenty-eight patients with cardiac amyloidosis were studied by echocardiography -- 26 by M-mode and 13 by two-dimensional (2D) studies. All had heart failure and biopsy-proved amyloidosis, M-mode features included (1) normal left ventricular (LV) dimension in all; (2) thickened ventricular septum (88%), LV posterior wall (77%), and right ventricular (RV) anterior wall (79%); (3) decreased thickening of ventricular septum (96%) and of LV posterior wall (65%) and reduced LV global function (62%); (4) left atrial enlargement (50%); and (5) pericardial effusion (58%). Two-dimensional echocardiography provided additional features: (1) thickened papillary muscles (five of 13); (2) thickened valves (four of 13); (3) better appreciation of thickened RV wall; and (4) a characteristic "granular sparkling" appearance of thickened cardiac walls -- presumably secondary to the amyloid deposit -- which was noted in 12 of 13 patients. Thus, M-mode echocardiography is helpful in the recognition of cardiac amyloidosis. However, the better appreciation with 2D echocardiography of thickened cardiac walls with a "granular sparkling" appearance in patients with unexplained cardiac failure is virtually diagnostic of cardiac amyloidosis.
Under steady-state conditions, urinary sodium excretion matches dietary sodium intake. Because extracellular fluid osmolality is tightly regulated, the quantity of sodium in the extracellular fluid determines the volume of this compartment. The left atrial volume receptor mechanism is an example of a neural mechanism of volume regulation. The left atrial mechanoreceptor, which functions as a sensor in the low-pressure vascular system, has a well-defined compliance relating intravascular volume to filling pressure and responds to changes in wall tension by discharging into afferent vagal fibers. These fibers have appropriate central nervous system representation whose related efferent neurohumoral mechanisms regulate thirst, renal excretion of water and sodium, and the redistribution of the extracellular fluid volume.
The aim of this study was to assess the value of routine transoesophageal echocardiography in the early postoperative period after mitral valve replacement. The authors report their experience in 50 consecutive operated patients (43 mechanical and 7 bioprostheses) investigated routinely by this method in the postoperative period in the surgical unit. Abnormal findings were observed in 36% of cases (18 patients): trans-prosthetic leaks (8 cases) and thrombosis (10 cases) in 2 bioprostheses and 8 mechanical prostheses; in 3 cases this led to haemodynamic dysfunction but in 7 cases the thrombus had no influence on the trans-prosthetic pressure gradient. No predisposing factor could be identified (spontaneous contrast, left atrial volume, left ventricular function, poor anticoagulation, blood clotting abnormalities). No abnormality of the mobile components of the prosthesis was observed at radioscopy. The outcome with heparin therapy was favourable with disappearance of the thrombi in 6 cases; the thrombi did not regress in 4 patients on heparin: 2 patients underwent thrombolytic therapy with a complete cure in 1 case and a severe embolic complication in the other; in 2 cases, the thrombus was so big that the patients were reoperated. Systematic early postoperative transoesophageal echocardiography before discharge from the surgical unit would seem to be necessary after early mitral valve replacement: it allows diagnosis of asymptomatic thrombosis which has an important emboligenic potential. The management of these thromboses remains controversial, but the poor natural outcome in cases of large thromboses should lead to referral for early reoperation.
Intracardiac thrombosis and cardioembolisms may have impressive effects on quality of life, prognosis and therapeutic costs in patients with valve disease or replacement devices. Distinct pathophysiological differences exist regarding intracardiac thrombus formation in low-versus high-pressure areas. Important cardiac confounders for low-pressure areas are left atrial geometry and function, including atrial fibrillation or loss of active atrial contraction. In high-pressure areas, flow velocity and shear stress are raised, and this may result in flow turbulence, for example when blood passes a stenotic area. Other major factors which correlate with intracardiac thrombus formation are implantation of polymer material and the degree of endocardial damage resulting for example, from infective or rheumatic endocarditis. Because of the interaction of platelets and the plasma clotting system, a combination of oral anticoagulation therapy and antiplatelet drugs should prevent more thromboembolic events than might anticoagulation alone. Recent studies in patients with prosthetic heart valves have indicated a positive risk-benefit profile if low-dose antiplatelet drugs are added to moderate intensive oral anticoagulation therapy. Thromboembolic events and bleeding complications due to oral anticoagulation therapy are accepted key parameters to demonstrate the superiority of one replacement device over another. However, there is no consistent system for reporting morbid events. In order to organize low and narrow target INR ranges, point-of-care patient self-testing modalities have been introduced and used effectively in large sample sizes. In the near future, some promising new drugs--including direct thrombin or factor Xa inhibitors with broader therapeutic ranges and thus fewer side effects--will become available. The test for these drugs will be their potential to prevent intracardiac thrombosis and cardioembolism in a patient population which is under significant risk.
BACKGROUND: Restoration of sinus rhythm in patients with atrial fibrillation (AF) is associated with an increased risk of thrombo-embolic complications due to delayed return of the left atrial and left atrial appendage systolic function. Direct current cardioversion (DC), used for AF termination, may cause myocardial injury and subsequent activation of inflammatory response. A C-reactive protein (CRP) is a non-specific marker of inflammation. AIM: To examine the effects of external DC of AF or atrial flutter (AFlut) on inflammatory processes. METHODS: The study group consisted of 35 patients (20 females and 15 males, mean age 67.9+/-9.7 years, range 46-83 years) with paroxysmal or persistent AF/AFlut who underwent elective DC. CRP plasma concentration was measured before and 24 hours after DC. RESULTS: The mean total DC energy was 431.2 J. CRP plasma concentration increased significantly following DC - from 3.9+/-3.4 ng/ml before DC to 7.2+/-6.7 ng/ml after DC (p<0.0001). CRP level correlated with body mass index (r=0.34, p<0.05), however, this correlation became non-significant after inclusion of the presence of diabetes into the statistical model. There was also a positive correlation between CRP values before and after DC (r=0.72, p<0.0001). No correlation between CRP and gender, total power of DC nor the number of DC shocks was detected. CONCLUSIONS: External DC of AF/Aflut causes activation of inflammatory processes measured as a significant increase in the CRP plasma concentration.
To analyze left atrial (LA) pump function, aortic root echocardiograms and LA pressure (P) by a Millar 's catheter tip manometer were recorded simultaneously in 26 patients (pts) in regular sinus rhythm [six normal subjects (C), three with angina pectoris (AP), eight with old myocardial infarction (MI), three with congestive cardiomyopathy (CCM), three with hypertension (HT), one with hypertrophic cardiomyopathy (HCM), one with mitral regurgitation and mild stenosis (MRs), and one with mitral regurgitation (MR)]. The pressure-dimension curve of the LA composed of two loops; an A-loop (pump function of the LA) and a V-loop. The following parameters were measured: Da = LA dimension at the beginning of the active atrial shortening, S-A-loop = the area of the A-loop, mean V = mean LA velocity of fractional fiber shortening, and peak T = maximum (LAP X LAD) during active atrial shortening phase. The S-A-loop was directly proportional to Da (r = 0.62, p less than 0.001) and the mean V was inversely correlated with the peak T (r = -0.76, p less than 0.001). This indicated that Starling's mechanism was operative and force-velocity relation exited in the LA. In HT, Da, the S-A-loop, the ratio of the S-A-loop to Da, and the ratio of mean V to peak T tended to be larger than those in other pts groups. Thus, the present results suggested that LA pump function was augmented in HT, probably due not only to Starling's effect but also to enhanced inotropic state of the LA.