Clinical Profile of Patients with Hypertensive Emergency Referred to a Tertiary Hospital in the Western Cape Province of South Africa.

BACKGROUND: Despite advances in managing hypertension, hypertensive emergencies remain a common indication for emergency room visits. Our study aimed to determine the clinical profile of patients referred with hypertensive emergencies. METHODS: We conducted an observational study involving patients aged ≥18 years referred with hypertensive crisis. A diagnosis of hypertensive emergencies was based on a systolic blood pressure (BP) ≥180 mmHg and/or a diastolic BP ≥110 mmHg, with acute hypertension-mediated organ damage (aHMOD). Patients without evidence of aHMOD were considered hypertensive urgencies. Hypertensive disorders of pregnancy and unconscious patients were excluded from the study. RESULTS: Eighty-two patients were included, comprising 66 (80.5%) with hypertensive emergencies and 16 (19.5%) with hypertensive urgencies. The mean age of patients with hypertensive emergencies was 47.9 (13.2) years, and 66.7% were males. Age, systolic BP, and duration of hypertension were similar in the hypertensive crisis cohort. Most patients with hypertensive emergencies reported nonadherence to medication (78%) or presented de novo without a prior diagnosis of hypertension (36%). Cardiac aHMOD (acute pulmonary edema and myocardial infarction) occurred in 66%, while neurological emergencies (intracranial hemorrhage, ischemic stroke, and hypertensive encephalopathy) occurred in 33.3%. Lactate dehydrogenase (LDH) (P < 0.001), NT-proBNP (P=0.024), and cardiac troponin (P<0.001) were higher in hypertensive emergencies compared to urgencies. LDH did not differ in the subtypes of hypertensive emergencies. CONCLUSION: Cardiovascular and neurological emergencies are the most common hypertensive emergencies. Most patients reported nonadherence to medication or presented de novo without a prior diagnosis of hypertension.

Myocardial Tissue Characterization in Patients with Hypertensive Crisis, Positive Troponin, and Unobstructed Coronary Arteries: A Cardiovascular Magnetic Resonance-Based Study.

Hypertensive crisis can present with cardiac troponin elevation and unobstructed coronary arteries. We used cardiac magnetic resonance (CMR) imaging to characterize the myocardial tissue in patients with hypertensive crisis, elevated cardiac troponin, and unobstructed coronary arteries. Patients with hypertensive crisis and elevated cardiac troponin with coronary artery stenosis <50% were enrolled. Patients with troponin-negative hypertensive crisis served as controls. All participants underwent CMR imaging at 1.5 Tesla. Imaging biomarkers and tissue characteristics were compared between the groups. There were 19 patients (63% male) with elevated troponin and 24 (33% male) troponin-negative controls. The troponin-positive group was older (57 ± 11 years vs. 47 ± 14 years, p = 0.015). The groups had similar T2-weighted signal intensity ratios and native T1 times. T2 relaxation times were longer in the troponin-positive group, and the difference remained significant after excluding infarct-pattern late gadolinium enhancement (LGE) from the analysis. Extracellular volume (ECV) was higher in the troponin-positive group (25 ± 4 ms vs. 22 ± 3 ms, p = 0.008) and correlated strongly with T2 relaxation time (rs = 0.701, p = 0.022). Late gadolinium enhancement was 32% more prevalent in the troponin-positive group (82% vs. 50%, p = 0.050), with 29% having infarct-pattern LGE. T2 relaxation time was independently associated with troponin positivity (OR 2.1, p = 0.043), and both T2 relaxation time and ECV predicted troponin positivity (C-statistics: 0.71, p = 0.009; and 0.77, p = 0.006). Left ventricular end-diastolic and left atrial volumes were the strongest predictors of troponin positivity (C-statistics: 0.80, p = 0.001; and 0.82, p < 0.001). The increased T2 relaxation time and ECV and their significant correlation in the troponin-positive group suggest myocardial injury with oedema, while the non-ischaemic LGE could be due to myocardial fibrosis or acute necrosis. These CMR imaging biomarkers provide important clinical indices for risk stratification and prognostication in patients with hypertensive crisis.

Cardiac Morphology, Function, and Left Ventricular Geometric Pattern in Patients with Hypertensive Crisis: A Cardiovascular Magnetic Resonance-Based Study.

(1) Background: Altered cardiac morphology and function are associated with increased risks of adverse cardiac events in hypertension. Our study aimed to assess left ventricular (LV) morphology, geometry, and function using cardiovascular magnetic resonance (CMR) imaging in patients with hypertensive crisis. (2) Methods: Patients with hypertensive crisis underwent CMR imaging at 1.5 Tesla to assess cardiac volume, mass, function, and contrasted study. Left ventricular (LV) function and geometry were defined according to the guideline recommendations. Late gadolinium enhancement (LGE) was qualitatively assessed and classified into ischemic and nonischemic patterns. Predictors of LGE was determined using regression analysis. (3) Results: Eighty-two patients with hypertensive crisis (aged 48.5 ± 13.4 years, and 57% males) underwent CMR imaging. Of these patients, seventy-eight percent were hypertensive emergency and twenty-two percent were urgency. Diastolic blood pressure was higher under hypertensive emergency (p = 0.032). Seventy-nine percent (92% of emergency vs. 59% of urgency, respectively; p = 0.003) had left ventricular hypertrophy (LVH). The most prevalent LV geometry was concentric hypertrophy (52%). Asymmetric LVH occurred in 13 (22%) of the participants after excluding ischemic LGE. Impaired systolic function occurred in 46% of patients, and predominantly involved hypertensive emergency. Nonischemic LGE occurred in 75% of contrasted studies (67.2% in emergency versus 44.4% in urgency, respectively; p < 0.001). Creatinine and LV mass were independently associated with nonischemic LGE. (5) Conclusion: LVH, altered geometry, asymmetric LVH, impaired LV systolic function, and LGE are common under hypertensive crisis. LVH and LGE more commonly occurred under hypertensive emergency. Longitudinal studies are required to determine the prognostic implications of asymmetric LVH and LGE in hypertensive crisis.

The Role of Cardiac Biomarkers in the Diagnosis of Hypertensive Emergency.

There is a growing interest in the role of biomarkers in differentiating hypertensive emergency from hypertensive urgency. This study aimed to determine the diagnostic utility of lactate dehydrogenase (LDH), high-sensitivity cardiac troponin T (hscTnT), and N-terminal prohormone of brain-type natriuretic peptide (NT-proBNP) for identifying hypertensive emergency. A diagnosis of hypertensive emergency was made based on a systolic blood pressure of ≥180 mmHg and/or a diastolic blood pressure of ≥110 mmHg with acute hypertension-mediated organ damage. The predictive value of LDH, hscTnT, NT-proBNP, and models of these biomarkers for hypertensive emergency was determined using the area under the receiver operator characteristic curve (AUC). There were 66 patients (66.7% male) with a hypertensive emergency and 16 (31.3% male) with hypertensive urgency. LDH, NT-proBNP, and hscTnT were significantly higher in hypertensive emergency. Serum LDH > 190 U/L and high creatinine were associated with hypertensive emergency. LDH had an AUC ranging from 0.87 to 0.92 for the spectrum of hypertensive emergencies, while hscTnT had an AUC of 0.82 to 0.92, except for neurological emergencies, in which the AUC was 0.72. NT-proBNP was only useful in predicting acute pulmonary edema (AUC of 0.89). A model incorporating LDH with hscTnT had an AUC of 0.92 to 0.97 for the spectrum of hypertensive emergencies. LDH in isolation or combined with hscTnT correctly identified hypertensive emergency in patients presenting with hypertensive crisis. The routine assessment of these biomarkers has the potential to facilitate the timely identification of hypertensive emergencies, especially in patients with subtle and subclinical target organ injury.

Altered cardiac structure and function in newly diagnosed people living with HIV: a prospective cardiovascular magnetic resonance study after the initiation of antiretroviral treatment.

HIV associated cardiomyopathy (HIVAC) is a poorly understood entity that may progress along a continuum. We evaluated a group of persons newly diagnosed with HIV and studied the evolution of cardiac abnormalities after ART initiation. We recruited a group of newly diagnosed, ART naïve persons with HIV and a healthy, HIV uninfected group. Participants underwent comprehensive cardiovascular evaluation, including cardiovascular magnetic resonance imaging. The HIV group was started on ART and re-evaluated 9 months later. The cardiovascular parameters of the study groups were compared at diagnosis and after 9 months. The ART naïve group's (n = 66) left- and right end diastolic volume indexed for height were larger compared with controls (n = 22) (p < 0.03). The left ventricular mass indexed for height was larger in the naïve group compared with controls (p = 0.04). The ART naïve group had decreased left- and right ventricular ejection fraction (p < 0.03) and negative, non-linear associations with high HIV viral load (p = 0.02). The left ventricular size increased after 9 months (p = 0.04), while the systolic function remained unchanged. The HIV group had a high rate of non-resolving pericardial effusions. HIV infected persons demonstrate structurally and functionally altered ventricles at diagnosis. High HIV viral load was associated with left- and right ventricular dysfunction. Cardiac parameters and pericardial effusion prevalence did not show improvement with ART. Conversely, a concerning trend of increase was observed with left ventricular size. These subclinical cardiac abnormalities may represent a stage on the continuum of HIVAC that can progress to symptomatic disease if the causes are not identified and addressed.

Prevalence of Aortic Root Dilation and Correlates of Aortic Root Dimensions in Treatment Naïve Hypertensive Patients in North-Eastern Nigeria.

Background: Systemic arterial hypertension is an independent predictor of cardiovascular diseases including aortic root dilation. Aortic root dilation is a hypertension-mediated organ damage entity regardless of age, gender, and body size. This study aims at determining the prevalence and associations of aortic root dilatation among treatment naïve hypertensive patients. Methodology: The study was a cross-sectional study conducted at the University of Maiduguri Teaching Hospital from June 2019 to June 2021. Study participants were treatment naïve hypertensive patients recruited consecutively from the outpatient clinic of the hospital and normotensive sex- and age-matched controls. End diastolic aortic root diameter was measured using 2D transthoracic echocardiography at the annulus, sinuses of Valsalva, and Sinotubular junction by leading-edge to a leading-edge convention as recommended by the American Society of Echocardiography in parasternal long-axis view. Results: Three hundred treatment naïve hypertensive patients (39.0% females) and 300 health normotensive age-and sex-matched controls (38.3% females) were enrolled. The mean ages of the patients and controls were 46.4±12.5 years and 46.4 ± 12.4 years respectively. The mean aortic root diameter (in mm) was significantly higher in the treatment naïve hypertensive arm of the study at the levels [AoA (24.7 ± 3.9mm versus 22.5 ± 2.0mm, p = 0.002), SoV (33.1 ± 3.4mm versus 31.4 ± 3.4mm, p = 0.023), and STJ (27.8 ± 3.5mm versus 25.9 ± 2.2mm, p = 0.002)]. Males had larger absolute aortic root diameters than females, however, after indexing aortic root diameters for BSA, there was no significant difference. The prevalence of aortic root dilatation amongst the treatment naïve hypertensive patients was 1.3% at all considered levels. Conclusion: The aortic root dimensions in the treatment naïve hypertensive patients were larger than in normotensive adults. The prevalence of aortic root dilation at all levels amongst treatment naïve hypertensive patients is 1.3%.

Evolution of myocardial oedema and fibrosis in HIV infected persons after the initiation of antiretroviral therapy: a prospective cardiovascular magnetic resonance study.

BACKGROUND: Human immunodeficiency virus (HIV) infected persons on antiretroviral therapy (ART) have been shown to have functionally and structurally altered ventricles and may be related to cardiovascular inflammation. Mounting evidence suggests that the myocardium of HIV infected individuals may be abnormal before ART is initiated and may represent subclinical HIV-associated cardiomyopathy (HIVAC). The influence of ART on subclinical HIVAC is not known. METHODS: Newly diagnosed, ART naïve persons with HIV infection were enrolled along with HIV uninfected, age- and sex-matched controls. All participants underwent comprehensive cardiovascular assessment, including contrasted cardiovascular magnetic resonance (CMR) with multiparametric mapping on a 1.5T CMR system. The HIV group was started on ART (tenofovir/lamivudine/dolutegravir) and prospectively evaluated 9 months later. Cardiac tissue characterisation was compared in, and between groups using the appropriate statistical tests for the cross sectional data and the paired, prospective data respectively. RESULTS: Seventy-three ART naïve HIV infected individuals (32 ± 7 years, 45% female) and 22 healthy non-HIV subjects (33 ± 7 years, 50% female) were enrolled. Compared with non-HIV healthy subjects, the global native T1 (1008 ± 31 ms vs 1032 ± 44 ms, p = 0.02), global T2 (46 ± 2 vs 48 ± 3 ms, p = 0.006), and the prevalence of pericardial effusion (18% vs 67%, p < 0.001) were significantly higher in the HIV infected group at diagnosis. Global native T1 (1032 ± 44 to 1014 ± 34 ms, p < 0.001) and extracellular volume (ECV) (26 ± 4% to 25 ± 3%, p = 0.001) decreased significantly after 9 months on ART and were significantly associated with a decrease in the HIV viral load, decreased high sensitivity C-reactive protein, and improvement in the CD4 count (p < 0.001). Replacement fibrosis was significantly higher in the HIV infected group than controls (49% vs 10%, p = 0.02). The prevalence of late gadolinium enhancement did not change significantly over the 9-month study period (49% vs 55%, p = 0.4). CONCLUSION: Subclinical HIVAC may already be present at the time of HIV diagnosis, as suggested by the combination of subclinical myocardial oedema and fibrosis found to be present before administration of ART. Markers of myocardial oedema on tissue characterization improved on ART in the short term, however, it is unclear if the underlying pathological mechanism is halted, or merely slowed by ART. Mid- to long term prospective studies are needed to evaluate subtle myocardial changes over time and to assess the significance of subclinical myocardial fibrosis.

Cardiac Complications of Hypertensive Emergency: Classification, Diagnosis and Management Challenges.

While mortality in patients with hypertensive emergency has significantly improved over the past decades, the incidence and complications associated with acute hypertension-mediated organ damage have not followed a similar trend. Hypertensive emergency is characterized by an abrupt surge in blood pressure, mostly occurring in people with pre-existing hypertension to result in acute hypertension-mediated organ damage. Acute hypertension-mediated organ damage commonly affects the cardiovascular system, and present as acute heart failure, myocardial infarction, and less commonly, acute aortic syndrome. Elevated cardiac troponin with or without myocardial infarction is one of the major determinants of outcome in hypertensive emergency. Despite being an established entity distinct from myocardial infarction, myocardial injury has not been systematically studied in hypertensive emergency. The current guidelines on the evaluation and management of hypertensive emergencies limit the cardiac troponin assay to patients presenting with features of myocardial ischemia and acute coronary syndrome, resulting in underdiagnosis, especially of atypical myocardial infarction. In this narrative review, we aimed to give an overview of the epidemiology and pathophysiology of hypertensive emergencies, highlight challenges in the evaluation, classification, and treatment of hypertensive emergency, and propose an algorithm for the evaluation and classification of cardiac acute hypertension-mediated organ damage.

Prevalence of Myocardial Injury and Myocardial Infarction in Patients with a Hypertensive Emergency: A Systematic Review.

Myocardial injury and myocardial infarction can complicate a hypertensive emergency, and both are associated with poor prognosis. However, little is known about the prevalence of myocardial injury and the different subtypes of myocardial infarction in patients with hypertensive emergencies. This systematic review aims to determine the prevalence of myocardial infarction and its subtypes, and the prevalence of myocardial injury in patients with hypertensive emergencies following the PRISMA guideline. A systematic search of PubMed, Web of Science, and EBSCOHost (MEDLINE) databases was carried out from inception to identify relevant articles. A total of 18 studies involving 7545 patients with a hypertensive emergency were included. Fifteen (83.3%) studies reported on the prevalence of myocardial infarction ranging from 3.6% to 59.6%, but only two studies specifically indicated the prevalence of ST-elevation and non-ST-elevation myocardial infarction. The prevalence of myocardial injury was obtained in three studies (16.7%) and ranged from 15% to 63%. Despite being common, very few studies reported myocardial injury and the subtypes of myocardial infarction among patients presenting with a hypertensive emergency, highlighting the need for more research in this area which will provide pertinent data to guide patient management and identify those at increased risk of major adverse cardiovascular events.

Digoxin and Symptomatic Bradyarrhythmia: the 'demon' or a 'red herring'.

Digoxin toxicity has been implicated in all forms of cardiac arrhythmias with the notable exception of Mobitz II atrioventricular block, which is very rare. The manifestation is quite variable, ranging from being asymptomatic to gastrointestinal, cardiac, and neurologic symptoms. The manifestations can be protean in the elderly, the most vulnerable group, where degenerative cardiac conduction system diseases add another layer of intrigue by providing an intrinsic substrate for cardiac dysrhythmia. This is in addition to age-related alteration of digoxin pharmacokinetics, use of multiple medications, chronic conditions, and electrolyte derangement, all of which increase the propensity for digoxin toxicity. We present a case of various atrioventricular conduction blocks in a septuagenarian following the use of digoxin.

Clinical Features and Outcomes of Peripartum Cardiomyopathy in Nigeria.

BACKGROUND: Nigeria has the highest incidence of peripartum cardiomyopathy (PPCM) in the world. However, data on PPCM-related outcomes are limited. OBJECTIVES: The purpose of this study was to examine the clinical profile, myocardial remodeling, and survival of patients with PPCM in Nigeria. METHODS: This study consecutively recruited 244 PPCM patients (median 7 months postpartum) at 14 sites in Nigeria and applied structured follow-up for a median of 17 months (interquartile range: 14 to 20 months). Left ventricular reverse remodeling (LVRR) was defined as the composite of left ventricular (LV) end-diastolic dimension <33 mm/m2 and absolute increase in left ventricular ejection fraction (LVEF) ≥10%. LV full recovery was defined as LVEF ≥55%. RESULTS: Overall, 45 (18.7%) patients died during follow-up. Maternal age <20 years (hazard ratio [HR]: 2.40; 95% confidence interval (CI): 1.27 to 4.54), hypotension (HR: 1.87; 95% CI: 1.02 to 3.43), tachycardia (HR: 2.38; 95% CI: 1.05 to 5.43), and LVEF <25% at baseline (HR: 2.11; 95% CI: 1.12 to 3.95) independently predicted mortality. Obesity (HR: 0.16; 95% CI: 0.04 to 0.55) and regular use of beta-blockers at 6-month follow-up (HR: 0.20; 95% CI: 0.09 to 0.41) were independently associated with reduced risk for mortality. In total, 48 patients (24.1%) achieved LVRR and 45 (22.6%) achieved LV full recovery. LVEF <25% at baseline (HR: 0.66; 95% CI: 0.47 to 0.92) and regular use of beta-blockers at 6-month follow-up (HR: 1.62; 95% CI: 1.17 to 2.25) independently determined the risk for LV full recovery. Progressive reverse remodeling of all cardiac chambers was observed. In total, 18 patients (7.4%) were hospitalized during the study. CONCLUSIONS: This is the largest study of PPCM in Africa. Consistent with late presentations, the mortality rate was high, whereas frequencies of LVRR and LV full recovery were low. Several variables predicted poor outcomes, and regular use of beta-blockers correlated with late survival and LV functional recovery.

Cardiac Pacing Training in Africa: Endorsed by the Africa Heart Rhythm Association (AFHRA): JACC International.

The field of pacing in Africa has evolved in an uncoordinated way across the continent with significant variation in local expertise, cost, and utilization. There are many countries where pacemaker services do not meet one-hundredth of the national demand. Regional, national, and institutional standards for pacemaker qualification and credentials are lacking. This paper reviews the current needs for bradycardia pacing and evaluates what standards should be set to develop pacemaker services in a resource-constrained continent, including the challenges and opportunities of capacity building and training as well as standards for training programs (training prerequisites, case volumes, program content, and evaluation).

Hypertrophic Cardiomyopathy and Wolff-Parkinson-White Syndrome in a Young African Soldier with Recurrent Syncope.

Syncope is a common manifestation of both hypertrophic cardiomyopathy (HCM) and Wolff-Parkinson-White (WPW) syndrome. The most common arrhythmia in HCM is ventricular tachycardia (VT) and atrial fibrillation (AF). While preexcitation provides the substrate for reentry and supraventricular tachycardia (SVT), AF is more common in patients with preexcitation than the general population. Concurrence of HCM and WPW has been reported in many cases, but whether the prognosis or severity of arrhythmia is different compared to the individual disorders remains unsettled. We report a case of HCM and Wolff-Parkinson-White (WPW) syndrome in a 28-year-old male Nigerian soldier presenting with recurrent syncope and lichen planus.

Statistics on the use of cardiac electronic devices and interventional electrophysiological procedures in Africa from 2011 to 2016: report of the Pan African Society of Cardiology (PASCAR) Cardiac Arrhythmias and Pacing Task Forces.

Aims: To provide comprehensive information on the access and use of cardiac implantable electronic devices (CIED) and catheter ablation procedures in Africa. Methods and results: The Pan-African Society of Cardiology (PASCAR) collected data on invasive management of cardiac arrhythmias from 2011 to 2016 from 31 African countries. A specific template was completed by physicians, and additional information obtained from industry. Information on health care systems, demographics, economics, procedure rates, and specific training programs was collected. Considerable heterogeneity in the access to arrhythmia care was observed across Africa. Eight of the 31 countries surveyed (26%) did not perform pacemaker implantations. The median pacemaker implantation rate was 2.66 per million population per country (range: 0.14-233 per million population). Implantable cardioverter-defibrillator and cardiac resynchronization therapy were performed in 12/31 (39%) and 15/31 (48%) countries respectively, mostly by visiting teams. Electrophysiological studies, including complex catheter ablations were performed in all countries from Maghreb, but only one sub-Saharan African country (South Africa). Marked variation in cost (up to 1000-fold) was observed across countries with an inverse correlation between implant rates and the procedure fees standardized to the gross domestic product per capita. Lack of economic resources and facilities, high cost of procedures, deficiency of trained physicians, and non-existent fellowship programs were the main drivers of under-utilization of interventional cardiac arrhythmia care. Conclusion: There is limited access to CIED and ablation procedures in Africa. A quarter of countries did not have pacemaker implantation services, and catheter ablations were only available in one country in sub-Saharan Africa.

Myocardial changes in incident haemodialysis patients over 6-months: an observational cardiac magnetic resonance imaging study.

Patients commencing on haemodialysis (HD) have an increased risk of cardiovascular events in the first year after starting HD compared to those patients established on HD longer. Left ventricular (LV) hypertrophy and abnormal myocardial strain predict mortality. There may be changes in the myocardium of incident HD patients over a 6-month period of HD which may explain changes in cardiovascular risk. We used CMR to consider changes in LV mass, myocardial strain and T1 mapping. We examined changes in pre-dialysis highly sensitive troponin T. 33 patients undergoing HD for <12 months were recruited. Participants underwent CMR at baseline and after 6-months of standard care. 6-months of HD was associated with reduction in LV mass index (Baseline: 78.8 g/m2 follow up: 69.9 g/m2, p = <0.001). LV global longitudinal strain also improved (Baseline: -17.9%, follow up: -21.6%, p = <0.001). Change in T1 time was not significant (Baseline septal T1 1277.4 ms, follow up 1271.5 p = 0.504). Highly sensitive troponin T was lower at follow up (Baseline 38.8 pg/L, follow up 30.8 pg/L p = 0.02). In incident HD patients, 6-months of HD was associated with improvements in LV mass, strain and troponin. These findings may reflect improvement in known cardiac tissue abnormalities found in patients over the first year of HD.

Inappropriate implantable cardioverter-defibrillator shocks in Brugada syndrome: Pattern in primary and secondary prevention.

BACKGROUND: Inappropriate implantable cardioverter-defibrillator (ICD) shocks is a common complication in Brugada syndrome. However, the incidence in recipients of ICD for primary and secondary prevention is unknown. METHOD AND RESULTS: We compared the rate of inappropriate shocks in patients with Brugada syndrome that had an ICD for primary and secondary prevention. We studied 51 patients, 86.5% of whom were males. Their mean age at diagnosis was 47 ± 11 years. Eighteen (35%) were asymptomatic, while 25 (49%) experienced syncope prior to implantation. Eight (16%) patients were resuscitated from ventricular fibrillation before implantation. During a mean follow-up of 78 ± 46 months, none of the asymptomatic patients experienced appropriate therapy, whereas 21.6% of symptomatic patients had ≥1 shock. Inappropriate shock occurred in 7 (13.7%) patients, with a mean IS of 6.57 ± 6.94 shocks per patient occurring 16.14 ± 10.38 months after implantation. There was a trend towards higher incidence of inappropriate shock in the asymptomatic group (p = 0.09). The interval from implantation to inappropriate shock occurrence was 13.91 ± 12.98 months. The risk of IS at 3 years was 13.7%, which eventually plateaued over the time. CONCLUSION: Inappropriate shock is common in Brugada syndrome during the early periods after an ICD implantation, and seems to be more likely in asymptomatic patients. This finding may warrant a review of the indications for ICD implantation, especially in the young and apparently healthy population of patients with Brugada syndrome.

Defining myocardial tissue abnormalities in end-stage renal failure with cardiac magnetic resonance imaging using native T1 mapping.

Noninvasive quantification of myocardial fibrosis in end-stage renal disease is challenging. Gadolinium contrast agents previously used for cardiac magnetic resonance imaging (MRI) are contraindicated because of an association with nephrogenic systemic fibrosis. In other populations, increased myocardial native T1 times on cardiac MRI have been shown to be a surrogate marker of myocardial fibrosis. We applied this method to 33 incident hemodialysis patients and 28 age- and sex-matched healthy volunteers who underwent MRI at 3.0T. Native T1 relaxation times and feature tracking-derived global longitudinal strain as potential markers of fibrosis were compared and associated with cardiac biomarkers. Left ventricular mass indices were higher in the hemodialysis than the control group. Global, Septal and midseptal T1 times were all significantly higher in the hemodialysis group (global T1 hemodialysis 1171 ± 27 ms vs. 1154 ± 32 ms; septal T1 hemodialysis 1184 ± 29 ms vs. 1163 ± 30 ms; and midseptal T1 hemodialysis 1184 ± 34 ms vs. 1161 ± 29 ms). In the hemodialysis group, T1 times correlated with left ventricular mass indices. Septal T1 times correlated with troponin and electrocardiogram-corrected QT interval. The peak global longitudinal strain was significantly reduced in the hemodialysis group (hemodialysis -17.7±5.3% vs. -21.8±6.2%). For hemodialysis patients, the peak global longitudinal strain significantly correlated with left ventricular mass indices (R = 0.426), and a trend was seen for correlation with galectin-3, a biomarker of cardiac fibrosis. Thus, cardiac tissue properties of hemodialysis patients consistent with myocardial fibrosis can be determined noninvasively and associated with multiple structural and functional abnormalities.

Rationale and design of the Pan-African Sudden Cardiac Death survey: the Pan-African SCD study.

BACKGROUND: The estimated rate of sudden cardiac death (SCD) in Western countries ranges from 300,000 to 400,000 annually, which represents 0.36 to 1.28 per 1 000 inhabitants in Europe and the United States. The burden of SCD in Africa is unknown. Our aim is to assess the epidemiology of SCD in Africa. METHODS: The Pan-Africa SCD study is a prospective, multicentre, community-based registry monitoring all cases of cardiac arrest occurring in victims over 15 years old. We will use the definition of SCD as 'witnessed natural death occurring within one hour of the onset of symptoms' or 'unwitnessed natural death within 24 hours of the onset of symptoms'. After approval from institutional boards, we will record demographic, clinical, electrocardiographic and biological variables of SCD victims (including survivors of cardiac arrest) in several African cities. All deaths occurring in residents of districts of interest will be checked for past medical history, circumstances of death, and autopsy report (if possible). We will also analyse the employment of resuscitation attempts during the time frame of sudden cardiac arrest (SCA) in various patient populations throughout African countries. CONCLUSION: This study will provide comprehensive, contemporary data on the epidemiology of SCD in Africa and will help in the development of strategies to prevent and manage cardiac arrest in this region of the world.

Prevalence and Aetiology of Left Ventricular Thrombus in Patients Undergoing Transthoracic Echocardiography at the University of Maiduguri Teaching Hospital.

Objectives. We sought to determine the prevalence and aetiology of LVT among patients undergoing echocardiography. Methods. We reviewed case notes and echocardiographic data of patient diagnosed with LVT using noncontrast transthoracic echocardiography. Definition of various conditions was made using standard guidelines. Mean ± SD were derived for continuous variables and comparison was made using Student's t-test. Results. Total of 1302 transthoracic echocardiograms were performed out of which 949 adult echocardiograms were considered eligible. Mean age of all subjects with abnormal echocardiograms was 44.73 (16.73) years. Abnormalities associated with LVT were observed in 782/949 (82.40%) subjects among whom 84/782 (8.85%) had LVT. The highest prevalence of 39.29% (33/84) was observed in patients with dilated cardiomyopathy, followed by myocardial infarction with a prevalence of 29.76% (25/84). Peripartum cardiomyopathy accounted for 18/84 (21.43%) cases with some having multiple thrombi, whereas hypertensive heart disease was responsible for 6/84 (7.14%) cases. The lowest prevalence of 2.38% (2/84) was observed in those with rheumatic heart disease. Left ventricular EF of <35% was recorded in 55/84 (65.48%). Conclusions. Left ventricular thrombus is common among patients undergoing echo, with dilated cardiomyopathy being the most common underlying aetiology followed by myocardial infarction. Multiple LVTs were documented in peripartum cardiomyopathy.