Carotid atherosclerosis and right ventricular diastolic dysfunction in a sample of hypertensive Nigerian patients

Aim

To determine the association of carotid atherosclerosis and right ventricular diastolic dysfunction (DD) among treated hypertensive Nigerian patients.

Methods

This was a single center cross-sectional study performed at the Cardiology Clinic of LAUTECH Teaching Hospital, Ogbomoso, Nigeria between January and December 2012. The study included 122 hypertensive Nigerians (mean age, 57.3 ± 14.7 years, 36.9% women). Patients’ clinical, demographic, and echocardiographic parameters were obtained. Diastolic dysfunction was assessed with the trans-tricuspid Doppler flow.

Results

Patients with DD were significantly older than those with normal diastolic function. Mean and maximum carotid intima media thickness measurements were significantly higher among patients with right ventricular DD than in those with normal diastolic function. Mean systolic blood pressure (148.3 ± 31.9 vs 128.0 ± 2.8 mm Hg, P = 0.049) and interventricular septal thickness in diastole (12.8 ± 2.3 vs 11.6 ± 2.8mm, P = 0.048) were significantly higher and tricuspid annular pulmonary systolic excursion (33.6 ± 4.9 vs 23.0 ± 4.2 mm, P = 0.035) was significantly lower in patients with right ventricular DD than in those with normal diastolic function. Carotid intima media thickness measurements were correlated with early trans-tricuspid Doppler flow and early transtricuspid diastolic flow/late right atrial transtricupsid diastolic flow ratio.

Conclusion

Right ventricular DD in hypertensive patients was significantly correlated with increased carotid atherosclerosis. Carotid intima media thickness measurements may therefore be a surrogate marker for DD in hypertensive subjects.Systemic hypertension has been shown to be associated with right ventricular abnormalities in both morphology and function. Right ventricular diastolic dysfunction (DD) may be an early indicator of hypertensive heart disease accompanying left ventricular DD (1-3). It can be diagnosed by various means including the ratio of early and late trans-tricuspid Doppler inflow velocities and tissue Doppler velocities.Atherosclerosis is the underlying factor for many cases of cardiovascular morbidity and mortality (4). A useful surrogate marker for carotid atherosclerosis is carotid intima media thickness (5). This parameter reflects the severity of thickening/atherosclerosis of the major arteries and is directly linked with the severity of hypertension and target organ damage associated with hypertension (2,4). DD is a typical part of the cardiovascular risk spectrum with increased risk for accelerating progressive cardiac dysfunction (6). However, it is still not known whether carotid intima media thickness, which has been shown to correlate with many conventional cardiovascular risk factors, is associated with right ventricular DD, especially among Africans (7). This study aims to determine the association between right ventricular DD and carotid intima media thickness in a sample of Nigerian hypertensive patients.     

Beta-blockers for the treatment of problematic hemangiomas

OBJECTIVE:

To examine treatment indications, efficacy and side effects of oral beta-blockers for the treatment of problematic hemangiomas.

METHODS:

A retrospective review of patients with hemangiomas presenting to the Alberta Children’s Hospital Vascular Birthmark Clinic (Calgary, Alberta) between 2009 and 2011 was conducted. The subset of patients treated with oral beta-blockers was further characterized, investigating indication for treatment, response to treatment, time to resolution of indication, duration of treatment, occurrence of rebound growth and side effects of therapy.

RESULTS:

Between 2009 and 2011, 311 new patients with hemangiomas were seen, of whom 105 were treated with oral beta-blockers. Forty-five patients completed beta-blocker treatment while the remainder continue to receive therapy. Indications for treatment were either functional concerns (68.6%) or disfigurement (31.4%). Functional concerns included ulceration (29.5%), periocular location with potential for visual interference (28.6%), airway interference (4.8%), PHACES syndrome (3.8%), auditory interference (0.95%) and visceral location with congestive heart failure (0.95%). The median age at beta-blocker initiation was 3.3 months; median duration of therapy was 10.6 months; and median maximal treatment dose was 1.5 mg/kg/day for propranolol and 1.6 mg/kg/day for atenolol. Ninety-nine patients (94.3%) responded to therapy with size reduction, colour changes, softened texture and/or healing of ulceration. Rebound growth requiring an additional course of therapy was observed in 23 patients. Side effects from beta-blockers included cool extremities (26.7%), irritability (17.1%), lower gastrointestinal upset (14.3%), emesis (11.4%), hypotension (10.5%), poor feeding (7.6%), lethargy (4.8%), bronchospasm (0.95%) and rash (0.95%). Side effects did not result in complete discontinuation of beta-blocker treatment in any case; however, they prompted a switch to a different beta-blocker preparation in some cases. Resolution of the primary indication, requiring a median time of three months, occurred in 87 individuals (82.9%).

CONCLUSIONS:

Treatment of infantile hemangiomas with oral beta-blocker therapy is highly effective and well tolerated, with more than 94% of patients demonstrating a response to treatment and 90% showing resolution of the primary functional indication for treatment.     

Ventricular arrhythmias: Q-T prolongation and left ventricular hypertrophy in adult Nigerians with hypertensive heart disease

Seventy adult Nigerians with hypertensive heart disease (HHD) and 68 healthy controls were studied for ventricular arrhythmias (VA). The roles of QT prolongation and left ventricular hypertrophy in these arrhythmias were received. The mean age of the study population was 49.9 +/- 6.0 years. 14 (20.0%) patients had cardiac arrhythmias with 3 patients having premature ventricular contractions (PVC). Ten (14.3%) cases had QTc prolongation out of which 1 patient had PVC. Some factors that were found to be associated with QT prolongation in HHD include: left ventricular hypertrophy, persistently elevated systolic blood pressure and female gender. There was a positive correlation between left ventricular hypertrophy and QTc prolongation and also between QTc prolongation and frequency of ventricular arrhythmias.     

Arrhythmias: appraisal of symptoms by haemodynamic concepts

Arryhthmias can afflict any heart, even in the absence of disease. Given that Cardiac Output (CO) is a product of heart rate and stroke volume, the end-result of brady- and tachy-arrhythmias is the same: low CO with symptoms of low-output state. In bradyarrhythmias, myocardial inotropy operates maximally but the product of stroke volume and slow heart rate yields a low CO. In tacharryhthmias, myocardial inotropy is redundant because the product of low stroke volume arising from low Diastolic Filling Time (DFT) and heart rate also yields a low CO. The hallmark of extrasystole is the duplex of symptoms: dizziness followed by palpitation.     

Characteristics of a donor population in western Venezuela

To determine the characteristics of blood donors in western Venezuela, we collected data from 1983 to 1985 on 31,320 volunteer donors at the Blood Bank of the State of Zulia in Maracaibo. Fifty-nine percent of the donors were blood group O, 30 percent were group A, 9 percent were group B, and 2 percent were group AB. Most of the donors (93%) were Rh positive. One percent of donors had positive reactions to hepatitis B surface antigen, 3.15 percent for syphilis, 1.43 percent for antibodies to Trypanosoma cruzi, and 0.32 percent to human immunodeficiency virus antibodies. About one-half of the donors were between 18 and 30 years old, and only 10 percent were women. To determine if iron deficiency anemia was a cause for the small size of the female donor pool, we measured serum ferritin in 50 first-time female donors. Ten of these (20%) had serum ferritin values below normal, and the distribution of serum ferritin levels of all 50 was very similar to that reported for frequent donors in Europe and the United States, with a clustering of ferritin values between 10 and 70 ng per ml. The data indicate that blood donors in western Venezuela are markedly different from those in the United States and that iron supplementation may be indicated for female Venezuelan donors.