A relapsed Pseudomonas stutzeri prosthetic valve endocarditis: a case report and review of the literature

BACKGROUND

Pseudomonas stutzeri is a nonfluorescent denitrifying bacterium widely distributed in the environment, and it has also been isolated as an opportunistic pathogen from humans. It is a Gram-negative bacterium and a common inhabitant of soil and water.

CASE PRESENTATION

We report the case of a 51-year-old arab gentleman who has systemic lupus erythematous complicated by lupus nephritis and underwent renal transplantation twice. He underwent mitral valve replacement and 4 years later was diagnosed with prosthetic valve endocarditis caused by Pseudomonas stutzeri.

CONCLUSIONS

Literature review was conducted and revealed that this pathogen may be of a particular medical relevance in immunocompromised patients. Our case proves that early infection and relapse despite optimal antibiotics course are possible outcomes of Pseudomonas stutzeri endocarditis. To the best of our knowledge, this is the second case of fulminant early prosthetic valve endocarditis occurring only 1 month post-cardiac surgery with relapse despite a complete antibiotics course.

Disseminated histoplasmosis in a heart transplant recipient from Saudi Arabia: A case report

Histoplasma is endemic in North and Central America. We describe a case of disseminated histoplasmosis in a heart transplant recipient outside the known endemic areas. A 68-year-old gentleman known to have dilated cardiomyopathy. He underwent left ventricular assist device (LVAD) implantation in India and 2 years later did heart transplant in King Faisal Specialist and Research Center Hospital. Six weeks post-transplant he presented with headache and fever. All investigations were negative, and he was discharged home. Four days after discharge he presented with headache, fever, blurred vision, and an episode of loss of consciousness. Examination showed an ill looking patient who is highly febrile. Repeated work up showed pancytopenia. A repeat LP was negative. Bone marrow biopsy showed Small intracellular organisms. Extended work up revealed a positive Histoplasma urinary antigen, positive Histoplasma PCR from the bone marrow biopsy. Patient was started on Liposomal Amphotericin followed by Itraconazole with marker clinical improvement. This is the first reported case of disseminated Histoplasmosis in Saudi Arabia. We postulate that the patient had reactivation of a latent infection acquired at the time of LVAD insertion in India rather than donor derived infection by the negative fungal culture and PCR done on the donor's lung granuloma tissue.

Quantitative proteomics analysis reveals unique but overlapping protein signatures in HIV infections

BACKGROUND

Human immunodeficiency virus-1 (HIV-1) exploits human host factors to complete its life cycle. Hence, discovery of HIV-regulated host proteins markers would better our understanding of the virus life-cycle and its contribution to pathogenesis and discovery of objective diagnostic and prognostic molecules.

METHODS

We conducted holistic total proteomics analysis of three closely related study populations including patients with HIV type-1 (HIV-1) and HIV type-2 (HIV-2) as well as HIV-1 elite controllers (HIV-1-EC). Peripheral blood plasma (PBP) samples were subjected to label-free quantitative liquid-chromatography tandem mass-spectrometry (LC-MS/MS).

RESULTS

Over 314 unique PBP protein species were identified of which 100 (approx. 32%) were significantly differentially expressed (≥2 to ∞ - fold-change; p < 0.05) between the three sample cohorts. Of the 100 proteins, 91 were significantly changed between pairs of HIV-1 versus HIV-1-EC, while 83 of the 100 proteins differed significantly between HIV-2 and HIV-1-EC. Interestingly, 76 proteins (87.5%) overlap between the two data sets indicating that majority of these proteins share similar expression changes between HIV-1 and HIV-2 sample groups. Two of the identified proteins, XRCC5 and PSME1, were implicated in the early phase of the pathway network for HIV life cycle, while others were involved in infectious disease and disease of signal transduction. Among them were MAP2K1, RPL23A, RPS3, CALR, PRDX1, SOD2, LMNB1, PHB, and FGB. Despite the high degree of similarity in protein profiles of HIV-1 and HIV-2, six proteins differed significantly including ETFB, PHB2, S100A9, LMO2, PPP3R1 and Vif, a fragment of virion infectivity factor of HIV-1. Additionally, 15 proteins were uniquely expressed, and one of them (LSP1) is present only in HIV-1-EC but absent in HIV1 and HIV-2 and vice versa for the rest 14 proteins.

CONCLUSIONS

Altogether, we have identified HIV-specific/related protein expression changes that might potentially be capable of early diagnosis and prognosis of HIV diseases and other related infectious diseases.

Q-fever prosthetic valve endocarditis in a patient with SLE and antiphospholipid antibody syndrome

Q fever prosthetic valve endocarditis in association with antiphospholipid antibody syndrome (APS) in systemic lupus erythematosus (SLE) has not been previously reported. Here, we report a 22-year-old Saudi female diagnosed with SLE and APS. She had mitral valve replacement with bio-prosthesis five years earlier for Libman-Sack endocarditis. She presented with two months' history of fever, cough, palpitations, and progressive shortness of breath. A transthoracic echocardiogram showed a degenerative mitral valve prosthesis with a large mass causing severe obstruction. Open heart surgery revealed multiple masses on the mitral valve. PCR from the resected tissues was positive for Coxiella burnetii DNA. Q fever serology showed phase two IgG 1:2048, phase one IgG 1:512, and IgM 1:1024. The valve was replaced with a bio-prosthesis. She was well at 12 months of follow-up.

Thermal Hall Effect in a Phonon-Glass Ba_{3}CuSb_{2}O_{9}

A distinct thermal Hall signal is observed in a quantum spin liquid candidate Ba_{3}CuSb_{2}O_{9}. The transverse thermal conductivity shows a power-law temperature dependence below 50 K, where a spin gap opens. We suggest that because of the very low longitudinal thermal conductivity and the thermal Hall signals, a phonon Hall effect is induced by strong phonon scattering of orphan Cu^{2+} spins formed in the random domains of the Cu^{2+}-Sb^{5+} dumbbells in Ba_{3}CuSb_{2}O_{9}.

Slater to Mott Crossover in the Metal to Insulator Transition of Nd_{2}Ir_{2}O_{7}

We present an angle-resolved photoemission study of the electronic structure of the three-dimensional pyrochlore iridate Nd_{2}Ir_{2}O_{7} through its magnetic metal-insulator transition. Our data reveal that metallic Nd_{2}Ir_{2}O_{7} has a quadratic band, touching the Fermi level at the Γ point, similar to that of Pr_{2}Ir_{2}O_{7}. The Fermi node state is, therefore, a common feature of the metallic phase of the pyrochlore iridates. Upon cooling below the transition temperature, this compound exhibits a gap opening with an energy shift of quasiparticle peaks like a band gap insulator. The quasiparticle peaks are strongly suppressed, however, with further decrease of temperature, and eventually vanish at the lowest temperature, leaving a nondispersive flat band lacking long-lived electrons. We thereby identify a remarkable crossover from Slater to Mott insulators with decreasing temperature. These observations explain the puzzling absence of Weyl points in this material, despite its proximity to the zero temperature metal-insulator transition.

Middle Eastern Respiratory Syndrome Corona Virus (MERS CoV): case reports from a tertiary care hospital in Saudi Arabia

BACKGROUND AND OBJECTIVES

Middle Eastern respiratory syndrome caused by novel coronavirus (MERS CoV) has been a major public health challenge since it was first described in 2012 in Saudi Arabia. So far, there is no effective treatment for this serious illness, which features a high mortality rate. We report an initial experience of the use of ribavirin and interferon (IFN)-a2b in the management of MERS CoV at a tertiary care hospital.

DESIGN AND SETTINGS

A case series of 6 patients admitted with a confirmed diagnosis of MERS CoV were treated with ribavirin and IFN-a2b in addition to supportive management. The patients' demographics, clinical parameters, and outcomes were recorded. Fifty-four close contacts of these patients were screened for MERS CoV.

METHODS

Six patients with MERS CoV infection were included in this study. Four cases featured symptomatic disease, including pneumonia and respiratory failure, while 2 were asymptomatic close contacts of the MERS CoV patients. The MERS CoV infection was confirmed by reverse transcription-polymerase chain reaction detection of the consensus viral RNA targets upstream of the E gene (UPE) and open reading frame (ORF1b) on a sputum sample. The patients' demographics, comorbid conditions, time to diagnosis and initiation of treatment, and clinical outcomes were recorded.

RESULTS

Three out of 6 patients who had comorbid conditions died during the study period, while 3 had suc.cessful outcomes. The diagnosis and treatment was delayed by an average of 15 days in those patients who died. Only 2 close contacts out of the 54 screened (3.7%) were positive for MERS CoV.

CONCLUSION

Treatment with ribavirin and IFN-a2b may be effective in patients infected with MERS CoV. There appears to be a low infectivity rate among close contacts of MERS CoV patients.

Multi-recipient donor-transmitted tuberculosis

Tuberculosis (TB) rates among transplant recipients are 20-74 times higher than in the general population, and have a mortality rate of up to 30%. The majority are potentially preventable. Most cases are reactivated latent infection after immune suppression. Donor-transmitted TB is very rare. We report three cases of TB that were transmitted by organ transplantation from a single donor.

Renal Transplantation in Children

OBJECTIVE

Renal transplantation is the preferred method for the treatment of children in end-stage renal disease (ESRD). In this retrospective study, we analyzed the results at our center.

PATIENTS AND METHODS

Between November 1993 and June 2006, 86 children (50 boys and 36 girls) received organs from 50 living donors (LDTx) and 36 cadaveric donors (CDTx). Twenty children were <10 years. In addition to ESRD, some patients had one or more other high-risk factors, eg, abnormal lower urinary tract in 36 recipients (42%). The procedure was a preemptive transplantation in 28, and a retransplantation in 9 recipients. Induction immunosuppression used either antithymocyte globulin (43 cases) or anti-interleukin-2 receptor antibodies (20 cases).

RESULTS

Patients were followed for 6 to 150 months. There were 24 surgical complications (28%), 26 acute rejection episodes (33%), and 17 of systemic bacterial or viral infections. Two recipients died at 1 and 21 months. The 14 grafts were lost at 1 day to 87 months. The 1- and 10-year actuarial survival rates were 99% and 98%, respectively, for the recipients, and 88% and 84%, respectively, for the grafts. The 10-year actuarial graft survival rates were 98% in LDTx and 64% in CDTx; 86% in recipients >10 years old and 75% in recipients <10 years old. Abnormal urinary tract, pretransplantation dialysis, and transplant number showed no effect on graft survival. All pediatric recipients with functioning grafts are fully rehabilitated.

CONCLUSION

Renal transplantation is the preferred method of treatment for children in ESRD. Higher graft survival rates were achieved in older children and following LDTx.

Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances

Effective phytoremediation of soils contaminated by heavy metals depends on their availability to plant uptake that, in turn, may be influenced by either the existing soil humus or an exogenous humic matter. We amended an organic and a mineral soil with an exogenous humic acid (HA) in order to enhance the soil organic carbon (SOC) content by 1% and 2%. The treated soils were further enriched with heavy metals (Cu, Pb, Cd, Zn, Ni) to a concentration of 0, 10, 20, and 40 microg/g for each metal and allowed to age at room temperature for 1 and 2 months. After each period, they were extracted for readily soluble and exchangeable (2.5% acetic acid), plant-available (DTPA, Diethylentriaminepentaacetic acid), and occluded (1 N HNO(3)) metal species. Addition of HA generally reduced the extractability of the soluble and exchangeable forms of metals. This effect was directly related to the amount of added HA and increased with ageing time. Conversely, the potentially plant-available metals extracted with DTPA were generally larger with increasing additions of exogenous HA solutions. This was attributed to the formation of metal-humic complexes, which ensured a temporary bioavailability of metals and prevented their rapid transformation into insoluble species. Extractions with 1 N HNO(3) further indicated that the added metals were present in complexes with HA. The observed effects appeared to also depend on the amount of native SOC and its structural changes with ageing. The results suggest that soil amendments with exogenous humic matter may accelerate the phytoremediation of heavy metals from contaminated soil, while concomitantly prevent their environmental mobility.

Evaluation of patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris

OBJECTIVES

To evaluate patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris (UAP).

DESIGN

Retrospective, observational study.

SETTING

Tertiary referral cardiology centre in the United Kingdom serving a large Asian ethnic population.

SUBJECTS

White and Asian patients undergoing PTCA for UAP over a 2.5-year period at a UK referral cardiology centre from a comprehensive PTCA database. Data were also collated for all emergency admissions with unstable angina, or angina (type unspecified), to our institute.

MAIN OUTCOME MEASURES

Demographic and angiographic characteristics of patients undergoing PTCA. Frequency of usage of invasive cardiac procedures was determined in emergency angina admissions.

RESULTS

From January 1997 to July 1999, 435 White and 36 Asian patients underwent PTCA for UAP at our institute. Asian patients were on average 4.4 years younger (P=0.015), had 19.3% more diabetes (P=0.003) and 19.7% less smoking (P=0.007). Trends to more single vessel disease in Whites and more double vessel disease in Asians were observed, with similar rates of triple vessel disease. Interestingly, Asians also had trends towards more left-sided coronary artery disease and revascularisation, smaller vessels and less bail-out stenting. Asian patients were significantly less likely to undergo coronary angiography, OR 0.64 (CI 0.45-0.91, P=0.012), during the index admission, and showed a trend to less PTCA.

CONCLUSIONS

Asian patients with unstable angina pectoris appear to have clinical and angiographic differences from their White counterparts, and are less likely to have invasive cardiac procedures deployed. The reasons for these observations require elucidation and the prognostic significance of these findings is uncertain.

The spectrum of Fusarium infection in immunocompromised patients with haematological malignancies and in non-immunocompromised patients: a single institution experience over 10 years

Fusarium is a newly emerging fungal pathogen associated with significant morbidity and mortality in the immunocompromised host. We have reviewed our hospital's experience with Fusarium between 1985 and 1995. Fusarium species were isolated from 22 specimens, representing 11 patients. Cases were not clustered by time period. The median age of the patients was 36.5 years (range 17-69 years). The sources of the organism were 12 skin lesions from eight patients, seven blood cultures from two patients and one specimen each from a Hickman catheter tip, nail clippings and a bronchoalveolar lavage. Seven of the patients had chemotherapy-induced neutropenia when the Fusarium was isolated. Five of them developed invasive fusarosis during acute leukaemia induction treatment. They remained neutropenic, and none survived. The other two patients recovered from neutropenia and were treated successfully for this infection. The remaining four patients were not neutropenic or immunocompromised. Three grew Fusarium from skin or nail clippings and one from bronchial alveolar lavage (BAL). There was no evidence of invasive disease in any of the four. None of them received antifungal therapy, and they were all alive at last follow-up. We conclude that Fusarium is a newly emerging infection in neutropenic patients. A high index of suspicion, especially for skin lesions, will help in early diagnosis before systemic and visceral dissemination. Excision of the initial focus of infection and antifungal therapy, aided by speedy neutrophil recovery, are likely to protect patients threatened with these fatal infections. Fusarium isolated from non-neutropenic, non-immunosuppressed patients is not significant and does not merit systemic antifungal treatment.

Coronary artery stenting in unstable angina pectoris: a comparison with stable angina pectoris

OBJECTIVE

To compare early complication rates in unselected cases of coronary artery stenting in patients with stable v unstable angina.

SETTING

Tertiary referral centre.

PATIENTS

390 patients with stable angina pectoris (SAP) and 306 with unstable angina (UAP). Patients treated for acute myocardial infarction (primary angioplasty) or cardiogenic shock were excluded.

INTERVENTIONS

268 coronary stents were attempted in 211 patients (30.3%). Stents used included AVE (63%), Freedom (14%), NIR (7%), Palmaz-Schatz (5%), JO (5%), and Multilink (4%). Intravascular ultrasound was not used in any of the cases. All stented patients were treated with ticlopidine and aspirin together with periprocedural unfractionated heparin.

RESULTS

123 stents were successfully deployed in 99 SAP patients v 132 stents in 103 UAP patients. Failed deployment occurred with nine stents in SAP patients, v four in UAP patients (NS). Stent thrombosis occurred in four SAP patients and 11 UAP patients. Multivariate analysis showed no relation between stent thrombosis and clinical presentation (SAP v UAP), age, sex, target vessel, stent length, or make of stent. Stent thrombosis was associated with small vessel size (p < 0.001) and bailout stenting (p = 0.01) compared with elective stenting and stenting for suboptimal PTCA, with strong trends toward smaller stent diameter (p = 0.052) and number of stents deployed (p = 0.06). Most stent thromboses occurred in vessels < 3 mm diameter.

CONCLUSIONS

Coronary artery stenting in unstable angina is safe in vessels >/= 3 mm diameter, with comparable initial success and stent thrombosis rates to stenting in stable angina.

Massive intrapericardial lipoma, a rare cause of breathlessness. Investigations and management

Massive intrapericardial lipoma is a rare cause of breathlessness. We describe a case, review the literature and discuss the presentation, investigation and management of this disorder.

Preliminary experience of the DIAS computer model in providing insulin dose advice to patients with insulin dependent diabetes

The Diabetes Advisory System (DIAS) is a model of human glucose metabolism which predicts hourly blood glucose concentrations and provides advice on insulin dose. Its ability to provide appropriate advice was assessed in 20 well-controlled IDDM patients (mean (SD) age 38 (11), duration 17 (9) years; HbA1 8.8 (0.9)%, reference range 5.4-7.6%). Patients recorded blood glucose measurements, insulin dose and food intake for 4 days. These data were used to generate insulin dose advice by both DIAS and a diabetes specialist nurse. Patients were then allocated to follow either DIAS or nurse advice for a further 4 days. There was no significant difference in mean recorded blood glucose values or frequency of reported hypoglycaemia between the DIAS and nurse groups either before or after insulin dose adjustment. The DIAS model, however, generated significantly lower insulin dose advice than the nurse (median (range)% change in insulin dose: DIAS group -13.3% (-25.0 to +11.6) versus nurse group 0% (-8.7 to +2.5), P < 0.05). We conclude that, in the patients studied, DIAS provided insulin dose advice which maintained good short term control of diabetes, despite significant reductions in dose in some cases.

In vitro activity of quinupristin/dalfopristin, RP59500, against gram-positive clinical isolates

Synercid (quinupristin/dalfopristin, RP59500) is a new water-soluble streptogramin which offers some advantages over the commercially available antimicrobials against drug-resistant gram-positive bacteria. Its in vitro activity was compared with ampicillin, augmentin, penicillin, erythromycin, oxacillin and vancomycin against gram-positive bacteria isolated from clinical specimens. Of the 837 gram-positive bacteria tested 834 (99.6%) were inhibited by < 0.6-4.0 mg/l of Synercid. It had excellent activity against both staphylococci and streptococci, including methicillin-resistant staphylococci and vancomycin-resistant enterococci.

Neuroschistosomiasis myelopathy: case report

A case of intramedullary neuroschistosomal granuloma in a 15-year-old girl is reported. Despite the fact that Saudi Arabia is endemic for schistosomiasis, neuroschistosomiasis has rarely been reported from that country. A review of the literature on the incidence, pathogenesis, clinical patterns and management of neuroschistosomiasis, particularly myelopathy, is given.

Susceptibility of methicillin-resistant Staphylococcus aureus to minocycline and other antimicrobials

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) is on the rise, especially in nosocomial and intravenous-drug-abuse-related infections, with a concomitant increase in morbidity, mortality and health care costs. At present the drug of choice, vancomycin, which must be administered intravenously, is expensive and can cause serious side effects in vancomycin-intolerant patients. Recently, minocycline has received much attention as an antibiotic to combat the increasing frequency of MRSA-related infections. We tested 102 recent clinical isolates of MRSA from tertiary-care patients and found none to be resistant to minocycline, with minimum inhibitory concentrations of < 1-2 micrograms/ml. The only other drug that inhibited all the strains was vancomycin, followed by ciprofloxacin (87%), clindamycin (55%) and chloramphenicol (52%). Gentamicin, beta-lactams, tetracycline and trimethoprim-sulfamethoxazole had little or no activity against our isolates of MRSA.

Histologically advanced chronic hepatitis C treated with recombinant alpha-interferon: a randomized placebo-controlled double-blind cross-over study

Chronic hepatitis C is common in Saudi Arabia and most often presents in an advanced stage. To assess the response of patients to interferon, a randomized placebo-controlled double-blind study was undertaken. All but 1 patient had cirrhosis or fibrosis before interferon. After a 24-week observation period patients received alpha 2a interferon, 3 mega units sc tiw or placebo for 24 weeks, then the opposite treatment for another 24 weeks followed by 24 weeks of observation. Liver biopsies were performed before and after each of the treatment phases. Twenty-two out of 24 patients completed the study. The mean alanine aminotransferase (ALT) levels fell from 150.7 +/- 118.7 units/l to 91.0 +/- 42.6 units/l after 6 months interferon treatment (P = 0.03) but only 3 patients (14%) had complete normalization of mean ALT levels and 4 (18%) had > 50% reduction. The mean hepatitis activity index fell from 12.2 +/- 2.6 immediately before to 11.6 +/- 2.5 just after interferon (P = 0.4). After interferon there was an insignificant raise in 6-month mean ALT. Hepatitis C virus-RNA was positive in all 17 patients tested and remained so after treatment. Side-effects were mild and well tolerated. Alpha interferon 3 mega units tiw for 24 weeks is not an effective treatment of histologically advanced chronic hepatitis C.

Comparison between single (Inoue) and double balloon mitral valvuloplasty: immediate and short-term results

This study compared the results in 60 consecutive patients with severe rheumatic mitral stenosis, who underwent percutaneous double-balloon mitral valvuloplasty by means of a combination of 20 mm + 20 mm diameter balloon catheters (group A), with a similar group of 60 consecutive patients who underwent single (Inoue) balloon mitral valvuloplasty (group B). After balloon mitral valvuloplasty the hemodynamic measurements showed significant improvement in both groups: in groups A and B, respectively, mitral valve area calculated with the Gorlin formula increased from 0.9 +/- 0.2 to 2.1 +/- 0.5 cm2 (p less than 0.001) and from 0.8 +/- 0.2 to 1.9 +/- 0.4 cm2 (p less than 0.001). There was a significant improvement in cardiac functional status in both groups. There was no significant difference between the groups with regard to clinical or hemodynamic improvement, technical failure rate, inadequacy of dilatation, or complications. However, the double-balloon technique was more complex and involved a longer screening time--group A, 40 +/- 12 minutes; group B, 21 +/- 10 minutes (p less than 0.001). In our institution the disposable supplies used for the Inoue balloon technique were 40% more expensive than those used for the double-balloon technique.

Spontaneous esophageal perforation in herpes simplex esophagitis

A 32-yr-old, previously healthy man with severe chest pain of sudden onset was found to have purulent pericarditis and pleural effusions. Several days later, an esophagogram revealed a perforation of the thoracic esophagus. Endoscopy showed a picture highly suggestive of a late stage of an extensive herpes simplex virus (HSV) esophagitis. Biopsies revealed evidence of massive HSV infection, confirmed by immune microscopy and virus culture. At surgery, a mediastinal abscess was found, and an esophageal perforation was identified. These findings suggest that the etiology of the perforation was an unusually severe herpetic infection. To our knowledge, HSV esophagitis has not previously been implicated as the cause of spontaneous esophageal perforation.

Fuzzy Logic for medical expert systems

The use of linguistic approximation enables knowledge to be represented in a more meaningful way and this is especially important in medical domain as it involves a lot of subjective decision making; Fuzzy Logic, introduced by Zadeh, has the ability to represent this imprecise expression. In this paper, an alternative approach of Fuzzy Logic in handling the approximate reasoning in expert systems will be described. The approach does not use the General Modus Ponen on the compositional rule of inference, but instead it uses a collection of rules to specify the properties of the inference (in making decision). An example of medical domain is described as its application.

Percutaneous single- and double-balloon aortic valvotomy in adolescents and young adults with congenital aortic stenosis

Percutaneous balloon aortic valvotomy was attempted in six consecutive adolescents and young adults, (mean age 18 +/- 5 years), with severe congenital aortic valvular stenosis. Peak systolic aortic valve gradient measurement and aortography was performed before and immediately after valvotomy, and a 1-6 months follow-up. The single-balloon technique was used in two patients and the double-balloon technique in four patients. After balloon valvotomy the mean peak systolic aortic valve gradient (PSG) decreased from 122 +/- 53 to 43 +/- 20 mmHg (P less than 0.01). The haemodynamic improvement persisted at follow-up (PSG = 47 +/- 31 mmHg), except in one patient who had previously undergone aortic surgical valvotomy. One balloon valvotomy was unsuccessful, presumably because of the selection of an inappropriately small balloon. Two patients with critical aortic stenosis (PSG greater than 165 mmHg), who exhibited a thick aortic valve on echocardiography with a relatively small aortic root and annulus, had a dramatic reduction in PSG. However, the degree of aortic regurgitation increased significantly in both cases. The theoretical haemodynamic advantage of the double versus the single balloon techniques was confirmed in one patient. We have demonstrated that percutaneous balloon aortic valvotomy using either the single- or double-balloon technique is feasible in young adults with severe congenital aortic stenosis. Further studies are required both to define appropriate patients and the selection of balloon diameter and length.

Mechanism of mitral valve area increase by in vitro single and double balloon mitral valvotomy

The mechanism of mitral valve area increase by double balloon mitral valvotomy in vitro has not been defined, nor have the mitral valve area results achieved by single versus double balloon mitral valvotomy technique been compared. After a selection of 29 intact mitral valves excised at cardiac surgery from patients with a mitral valve area less than or equal to 1.5 cm2 was made, double balloon mitral valvotomy was attempted in 14 valves using two 20-mm diameter balloon catheters (group 1) and single balloon mitral valvotomy using a 20-mm balloon was undertaken in 15 valves (group 2). In group 1 the mitral valve area increased from 0.9 +/- 0.03 to 1.9 +/- 0.05 cm2 (mean +/- standard error of the mean) (p less than 0.001), with a mean anterior commissural split of 5.3 +/- 0.2 mm and a posterior split of 4.1 +/- 0.2 mm. Following single balloon valvotomy (group 2), the mean mitral valve area increased from 0.8 +/- 0.03 to 1.2 +/- 0.03 cm2 (p less than 0.001), with the mean anterior commissural split being 2.6 +/- 0.2 mm and the posterior 2.1 +/- 0.2 mm. Ten mitral valves from group 2 underwent a second dilatation using the double balloon technique and the mitral valve area increased further from 1.2 +/- 0.06 to 1.9 +/- 0.06 cm2 (p less than 0.001). Overall, commissural splitting occurred preferentially in calcified commissures (81%), as opposed to only 56% of noncalcified commissures. Commissural splitting is the manner in which mitral valve area increases after double balloon mitral valvotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Provocation and amplification of the transvalvular pressure gradient in rheumatic tricuspid stenosis

A low cardiac output and high compliance of the systemic venous system may mask a resting tricuspid diastolic gradient in patients with significant rheumatic tricuspid stenosis. Thirty-three patients (mean age 28 +/- 10 years) with rheumatic tricuspid stenosis evidenced by 2-dimensional echocardiography (doming and restricted motion of all 3 tricuspid valve leaflets) were studied to expose occult and to amplify borderline and basal tricuspid valve gradients. At cardiac catheterization, the right atrium and right ventricular pressures were recorded simultaneously in the basal state, after intravenous infusion of 200, 400, 500, 700 or 1,000 ml of normal saline until a mean right atrial pressure of 12 mm Hg was achieved, and after 0.6 mg of intravenous atropine. Eleven patients (33%) had a mean tricuspid diastolic gradient of greater than 2 mm Hg at rest (group 1). After 483 +/- 240 ml of saline infusion, the mean tricuspid diastolic gradient increased from 5 +/- 2 to 9 +/- 3 mm Hg (p less than 0.001), secondary to a marked rise in right atrial pressure from 8 +/- 3 to 12 +/- 2 mm Hg (p less than 0.001). Concomitantly, there was no increase in right ventricular end-diastolic pressure, although the heart rate increased from 76 +/- 13 to 79 +/- 12 beats/min (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic evaluation of porcine bioprostheses in the mitral position by Doppler echocardiography

Twenty-four patients with porcine bioprostheses in the mitral position were studied by Doppler echocardiography followed by cardiac catheterization within 24 hours. Doppler mean diastolic mitral valve gradient was calculated by a 3-point method and mitral valve area was determined by the pressure half-time method. Data from Doppler echocardiography and cardiac catheterization were compared. There was a strong correlation between Doppler echocardiography and catheterization-determined mean diastolic gradient: r = 0.9, standard error of estimate (SEE) = 1.4 mm/Hg (regression equation y = 0.63x + 1.41), p less than 0.001. There was also a strong correlation between Doppler echocardiography and catheterization-determined mitral valve area: r = 0.86, SEE = 0.18 cm2 (regression equation y = 0.64x + 0.52), p less than 0.001. Fourteen patients whose valvular function was considered normal by clinical evaluation had Doppler-calculated mean diastolic gradients of 4.5 to 9.5 mm Hg (mean 6.5 +/- 1.4); the Doppler-determined valve area was 1.15 to 2.0 cm2 (mean 1.54 +/- 0.3). Ten patients had a malfunctioning bioprosthesis, 7 had severe mitral regurgitation and 3 had stenosis. Valvular malfunction in all 10 patients was detected by Doppler echocardiography and confirmed by catheterization and angiocardiography. Nine patients underwent reoperation. Doppler hemodynamic evaluation of porcine bioprostheses in the mitral position provided noninvasive information comparable to that obtained by cardiac catheterization.

Endomyocardial fibrosis: report of eight cases

Endomyocardial fibrosis is a disease of unknown origin which has not previously been described in detail from the Middle East. The clinical, echocardiographic, hemodynamic and angiocardiographic findings in eight patients (five men and three women, mean age 38 years) are presented. Two patients had right-sided involvement, two had left-sided involvement and four had biventricular involvement. The presence of a small ventricle with obliteration of the apex and a large atrium is a two-dimensional echocardiographic finding highly suggestive of endomyocardial fibrosis. Hemodynamic characteristics of dip and plateau on ventricular pressure curves were present in six patients. Ventricular angiography was diagnostic in all cases. Endomyocardial biopsy yielded positive findings in three of six patients and is not essential for diagnosis.

Surgical treatment of mitral regurgitation caused by floppy valves: repair versus replacement

Between October 1969 and April 1980, 132 patients underwent operation for floppy mitral valve. The 46 patients in group A underwent valve replacement using an inverted, fresh, unstented, antibiotic-sterilized aortic homograft and the 86 patients in group B underwent valve repair. The onset of symptoms was sudden. More than 80% of the patients in both groups were in New York Association functional class III or IV. The dominant lesion in both groups was ruptured chordae to the posterior cusp (72% in group A and 58% in group B). There were five early deaths (11%) and 15 late deaths (32%) in group A and four early deaths (5%) and five late deaths (7%) in group B. The actuarial survival rate at 5 years was 62% in group A and 90% in group B. In group A, five patients (11%) had valve failure, which led to late death in two. Four patients (8%) in group A required reoperation. Two patients in group B developed a loud mitral systolic murmur soon after operation and required reoperation. Two patients in group B had thromboembolism before routine anticoagulation. Sixteen patients (61%) in group A and 56 (76%) in group B were functional class I after operation.