High prevalence of symptomatic bradyarrhythmias due to atrioventricular node-fascicular and sinus node-atrial disease in patients with mitral anular calcification

Mitral Annulus Calcification and Cardiac Conduction Disturbances: a DANCAVAS Sub-study

BACKGROUND

Due to its location very close to the bundle of His, mitral annulus calcification (MAC) might be associated with the development of atrioventricular (AV) conduction disturbances. This study assessed the association between MAC and AV conduction disturbances identified by cardiac implantable electronic device (CIED) use and electrocardiographic parameters. The association between MAC and traditional cardiovascular risk factors was also assessed.

METHODS

This cross-sectional study analyzed 14,771 participants, predominantly men aged 60–75 years, from the population-based Danish Cardiovascular Screening trial. Traditional cardiovascular risk factors were obtained. Using cardiac non-contrast computed tomography imaging, MAC scores were measured using the Agatston method and divided into absent versus present and score categories. CIED implantation data were obtained from the Danish Pacemaker and Implantable Cardioverter Defibrillator Register. A 12-lead electrocardiogram was available for 2,107 participants. Associations between MAC scores and AV conduction disturbances were assessed using multivariate regression analyses.

RESULTS

MAC was present in 22.4% of the study subjects. Participants with pacemakers for an AV conduction disturbance had significantly higher MAC scores (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.01–1.23) than participants without a CIED, whereas participants with a CIED for other reasons did not. Prolonged QRS-interval was significantly associated with the presence of MAC (OR, 1.45; 95% CI, 1.04–2.04), whereas prolonged PQ-interval was not. Female sex and most traditional cardiovascular risk factors were significantly associated with high MAC scores.

CONCLUSIONS

MAC was associated with AV conduction disturbances, which could improve our understanding of the development of AV conduction disturbances.

Mitral annular calcification and valvular dysfunction: multimodality imaging evaluation, grading, and management

Mitral annular calcification (MAC) refers to calcium deposition in the fibrous skeleton of the mitral valve. It has many cardiovascular associations, including mitral valve dysfunction, elevated cardiovascular risk, arrhythmias, and endocarditis. Echocardiography conventionally is the first-line imaging modality for anatomic assessment, and evaluation of mitral valve function. Cardiac computed tomography (CT) has demonstrated importance as an imaging modality for the evaluation and planning of related procedures. It also holds promise in quantitative grading of MAC. Currently, there is no universally accepted definition or classification system of MAC severity. We review the multimodality imaging evaluation of MAC and associated valvular dysfunction and propose a novel classification system based on qualitative and quantitative measurements derived from echocardiography and cardiac CT.

Mitral Annular Calcification and Calcific Mitral Stenosis: Role of Echocardiography in Hemodynamic Assessment and Management

As the life expectancy of the population continues to increase, mitral annular calcification has emerged as an important cause of mitral stenosis (MS), commonly referred to as calcific or degenerative MS. Mitral annular calcification results in valvular stenosis when calcification extends into the base of the mitral leaflet(s) and displaces the mitral valve hinge point(s) into the left ventricular inlet. Echocardiographic determination of mitral vale area is fraught with difficulties and often precludes using planimetry or the Hatle formula. Given the numerous confounders that affect transmitral flow in calcific MS, evaluation of lesion severity should incorporate flow-independent methods such as the continuity equation and the mitral valve dimensionless index. In light of the significant risks entailed, there is little enthusiasm for mitral valve replacement in patients with calcific MS. Transcatheter mitral valve replacement is generally offered on a compassionate use basis to patients deemed to be at high surgical risk.

The Harder the Heart, the Harder It Breaks: A Case of Complete Atrioventricular Block Secondary to Tertiary Hyperparathyroidism

The appearance of first-degree atrioventricular block and mitral annulus calcification in an end-stage renal failure patient with elevated parathyroid hormone levels should raise the suspicion of metastatic cardiac calcification. Measures should be taken to normalize the parathyroid hormone, calcium, and phosphorus levels to limit the progression of atrioventricular block. Exploration or removal of parathyroid glands should be considered if heart block worsens. 

Exercise behavior of degenerative mitral stenosis

Mitral annular calcification (MAC) is increasingly encountered, particularly among the elderly and those with chronic kidney disease, and is often associated with a transvalvular gradient. In contrast to rheumatic mitral stenosis relatively little is known about mitral stenosis due to MAC. We aimed to clarify whether exercise limitation in this group is primarily due to valvular obstruction or ventricular dysfunction resulting from multiple comorbidities. 20 patients with severe MAC (bulky calcium deposits which restricted leaflet motion) were submitted to supine bicycle exercise, measuring Doppler and echocardiographic parameters at baseline and during exercise. They were compared 1:1 to subjects matched for age, sex, and left ventricular wall thickness. At baseline MAC subjects had higher mean mitral valve gradients (MVG) than comparison subjects (7.5 ± 3.8 vs 1.6 ± 0.8 mm Hg, p < 0.0001), along with larger indexed left atrial volumes (54.4 ± 14.9 vs 34.0 ± 11.7 mL, p < 0.0001) and reduced left atrial strains (reservoir, conduit, and booster pump). With exercise MAC subjects reached higher levels of MVG (17.3 ± 8.4 vs 5.5 ± 2.5 mm Hg, p < 0.0001), and pulmonary artery systolic pressure (estimated from tricuspid regurgitant jet [TR] velocity) and displayed a moderate correlation between ΔMVG and ΔTR velocity (r² = 0.57). MAC subjects whose exercise MVG was ≥ 15 mm Hg all had a peak pulmonary artery systolic pressure > 60 mm Hg. MAC subjects also had relative chronotropic incompetence. Patients with severe MAC and a transvalvular gradient experience large increases in MVG and pulmonary pressure with exercise, similar to what has been described in rheumatic mitral stenosis. MAC may be an under-recognized cause of dyspnea and exercise intolerance in older patients.

Skin aging parameters: A window to heart block

BACKGROUND

Skin acts as a mirror to the internal state of the body.

HYPOTHESIS

We tried to find the relation between skin aging parameters and the incidence of degenerative AV block.

METHODS

This study included 97 patients divided into 2 groups; group D comprised 49 patients with advanced-degree AV block, and group C comprised the 48 matched control group. All were subjected to full history taking, thorough clinical examination, calculation of intrinsic skin aging score, and resting 12-lead surface electrocardiography (ECG). ECG for all patients assessed left ventricular end-systolic diameter, left ventricular end-diastolic diameter, ejection fraction, left atrium (LA) diameter, aortic root diameter, mitral annular calcification, aortic sclerosis. Coronary angiography was also performed when indicated for patients in group D.

RESULTS

Patients in group D had a higher percentages of uneven pigmentation, fine skin wrinkles, lax appearance, seborrheic keratosis, total score > 7 (38 [77.55%] vs 10 [20.83%]), mitral annular calcification score of 33 (67.34%) vs 5 (10.41%), aortic sclerosis score of 21 (42.85%) vs 4 (8.33%), and mean LA diameter of 39.98 ± 5.52 vs 36.21 ± 3 mm (P < 0.001). Total score > 6 is the best cutoff value to predict advanced-degree heart block with 89.79% sensitivity and 64.58% specificity. Seborrheic keratosis was the strongest independent predictor.

CONCLUSIONS

Any population with a total intrinsic skin aging score of >6 is at high risk for developing advanced-degree AV block and should undergo periodic ECG follow-up for early detection of any conduction disturbance in the early asymptomatic stages to minimize sudden cardiac death.

Clinical and Echocardiographic Features of Mitral Annular Calcium in Patients Aged ≤50 Years

Data regarding characteristics of young patients with mitral annular calcification (MAC) and its associations with other cardiovascular risk factors are scarce. Hence, we sought to characterize patients aged <50 years with MAC and to examine whether in these patients, MAC is also associated with cardiovascular risk factors. Consecutive patients who underwent an echocardiographic study were prospectively entered into a database. The database included clinical, laboratory, and echocardiographic parameters. The present study included 56 patients aged <50 years with a diagnosis of MAC. The mean age was 44.2 ± 6.9 years with a male-to-female ratio of 2.5:1. The prevalence of cardiovascular risk factors (30 patients [53%] hypertension, 17 patients [30%] diabetes mellitus, 24 patients [43%] dyslipidemia, 22 patients [39%] smoking) and established cardiovascular disease (22 patients [39%] coronary artery disease, 11 patients [19%] previous stroke) was substantially higher than expected for this age group. Twenty-nine patients (52%) had chronic kidney disease. Of these, 18 patients (62%) had end-stage kidney disease and 7 patients (24%) underwent renal transplantation. Fourteen patients (25%) and 3 patients (5%) had moderate or severe mitral regurgitation and mitral stenosis, respectively. Aortic valve disease was present in 37 patients (66%). Moderate or severe left ventricular dysfunction and left ventricular hypertrophy were identified in 9 patients (16%) and 31 patients (56%), respectively. In conclusion, the detection of MAC in a young patient should be regarded as a marker of atherosclerotic disease, chronic kidney disease, and aortic valve disease.

Mitral annular calcification is a predictor for incident atrial fibrillation

BACKGROUND

Mitral annular calcification (MAC) has been associated with adverse cardiovascular disease outcomes and stroke in longitudinal and community-based cohorts. Prospective data are limited on its association with atrial fibrillation (AF).

METHODS

We examined the association between MAC and the long-term risk of AF over 16 years of follow-up in participants in the original cohort of the Framingham Heart Study who attended a routine examination between 1979 and 1981. MAC was assessed by M-mode echocardiography. cox proportional-hazards models were used to estimate hazard ratios (hr) for incident af.

RESULTS

Of 1126 subjects who had adequate echocardiographic assessment and were AF-free at baseline, 149 (13%) had MAC. There were 217 cases of incident AF (42 in subjects with MAC). The age- and sex-adjusted incidence rate was 362 per 10,000 person-years in subjects with MAC compared with 185 per 10,000 person-years in those without MAC. In multivariable-adjusted analyses, MAC was associated with an increased risk of AF (HR 1.6, 95% CI 1.1-2.2). This association was attenuated upon further adjustment for left atrial size (HR 1.4, 95% CI 0.9-2.0).

CONCLUSIONS

The association between MAC and incident AF may be mediated partially through left atrial enlargement. These data suggest the importance of better understanding the mechanisms involved in cardiac valvular calcification.

Cardiac conduction defects associated with aortic and mitral valve calcification in dialysis patients

The prevalence of aortic valve and mitral valve or mitral annular calcification by echocardiography was studied in 66 dialysis patients and correlated with results of 24-h ambulatory and resting ECG data and 12-month survival. The well-known association of mitral valve or mitral annular calcification with cardiac conduction defects was confirmed. Those patients with mitral valve or mitral annular calcification demonstrated a higher prevalence of first-degree atrioventricular block and bundle branch block. Despite advanced age and these conduction defects, those patients with mitral valvular calcification did not show decreased survival at 12 months.

Long-term follow-up of patients with echocardiographically detected mitral anular calcium and comparison with age- and sex-matched control subjects

One hundred seven patients with echocardiographically documented mitral anular calcium (MAC) and 107 age- and sex-matched control subjects without MAC were studied and followed for a mean of 4.4 +/- 2.4 (standard deviation) years. Fourteen (7%) patients were lost to follow-up. Compared with the control group, patients with MAC had higher frequency of precordial murmurs (p less than 0.0001), cardiomegaly (p less than 0.0001), left atrial enlargement (p less than 0.0001), and rhythm and conduction disturbances (p less than 0.0001). During the follow-up, patients with MAC had higher incidence of valve replacement (p less than 0.0025), permanent pacemaker implantation (p less than 0.0025), congestive heart failure (p less than 0.0001), thromboembolic cerebrovascular event (p less than 0.01), sudden death (p less than 0.001) and total cardiac death (p less than 0.0001). However, the frequencies of myocardial infarction, coronary artery bypass surgery and angioplasty, endocarditis or noncardiac death were not significantly different between patients with MAC and the control subjects. Thus, patients with MAC have higher frequencies of precordial murmurs, cardiomegaly, left atrial and ventricular enlargement, rhythm and conduction disturbances. They more frequently undergo valve replacement and permanent pacemaker implantation, develop congestive heart failure and die of cardiac causes than age- and sex-matched control subjects.

Mitral annular calcification and coarctation of aorta

Although coarctation of the aorta is associated with various cardiac abnormalities, its association with mitral annular calcification (MAC) is not reported. We therefore report a 37-year-old patient with postductal coarctation of the aorta and MAC. Considered to be a degenerative process, MAC is usually seen in elderly patients. It is uncommon in patients less than 50 years old and rare before the age of 40 years. Previous studies have reported increased frequency of cardiac conduction disturbances in patients with MAC compared to age- and sex-matched controls. This is in agreement with complete right bundle-branch block noted on the electrocardiogram of our patient. Clinicopathologic correlative studies and long-term follow-up may determine how such conduction disturbances develop and progress.

Permanent cardiac pacing for brady-arrhythmia

The indications for and technology associated with permanent cardiac pacing have undergone major changes during the past decade. In contrast to the 1970s, most patients now receive cardiac pacing devices subsequent to the diagnosis of sick sinus syndrome. However, since this condition is prevalent in elderly patients, it is crucial that indications for pacing be critically evaluated and pacing recommended only for those with documented symptoms or marked abnormalities indicative of high risk for a subsequent cardiac event. This is particularly important because pacing has not been shown to influence survival in these patients. The technological advances in pacing devices during the last ten years now provide many desirable options. As a result, available pacemakers range from very simple to highly complex; accordingly, they have a wide range of prices. It is more important than ever to carefully select the appropriate pacing device for a given patient, since its cost, longevity, and required follow-up may differ greatly.

Calcific valvular aortic stenosis with and without mitral anular calcium

Seventy-six consecutive patients, mean age 66 +/- 9 years (+/- standard deviation), with isolated aortic valve replacement for calcific valvular aortic stenosis (AS) were studied. Mitral anular calcium (MAC) was detected by echocardiography in 45 patients (59%). Patients with MAC were older (p less than 0.01), had greater peak systolic aortic valve gradients (p less than 0.025), lower cardiac indexes (p less than 0.025) and smaller valve areas (p less than 0.05) than patients without MAC. Thirty-three percent of patients (15 of 45) with MAC required permanent pacemaker implantation after aortic valve replacement, compared with only 10% of patients (3 of 31) without MAC (p less than 0.025). During the follow-up of 7 years (mean 3.8 +/- 1.6), 27% of patients (12 of 45) with MAC died from cardiac causes, compared to only 7% (2 of 31) without MAC (p less than 0.025). Thus, patients with AS and MAC are older, have more severe AS, more frequently undergo permanent pacemaker implantation after aortic valve replacement and more frequently die of cardiac causes than patients with AS and no MAC during follow-up.

Clinical characteristics of patients younger than 60 years with mitral anular calcium: comparison with age- and sex-matched control subjects

The clinical characteristics of 107 patients younger than 60 years with mitral anular calcium (MAC) were compared with those of 107 age- and sex-matched control subjects. The patients with MAC included 55 men and 52 women, mean age 51 years. The control group included 55 men and 52 women, mean age 51 years. Patients with MAC had a higher prevalence of cardiomegaly on chest x-ray (p less than 0.0001), left atrial and left ventricular enlargement by echocardiography (p less than 0.0001), precordial murmurs (p less than 0.0001), diabetes mellitus (p less than 0.0001), systemic hypertension (p less than 0.025) and total conduction defects on surface electrocardiograms (p less than 0.0001) compared with the age- and sex-matched control subjects. The mean serum phosphorus and product of serum calcium and phosphorus were higher in patients with MAC (p less than 0.0025) than in the control subjects. The prevalence of coronary heart disease, aortic stenosis and hypertrophic cardiomyopathy and the mean serum cholesterol, triglyceride, total protein, albumin, creatinine, alkaline phosphatase and calcium levels were not significantly different between patients with MAC and the control subjects.

Arrhythmias in patients with mitral valve prolapse. Types, evaluation, and therapy

A wide spectrum of cardiac rhythm and conduction disorders occur in patients with all types of valvular heart disease. However, certain types of valvular disease have a special predilection for arrhythmias, including atrial and ventricular tachyarrhythmias as well as bradyarrhythmias, inherent to the etiology of the condition itself. Most notable in this regard is mitral valve prolapse, in which cardiac dysrhythmia is now recognized as the complication of highest frequency. The principal purpose of this article is the delineation of the characteristics and management of rhythm disorders in the mitral valve prolapse syndrome.

Correlation between calcific aortic stenosis diagnosed by two-dimensional echocardiography and cardiac catheterization

This retrospective study correlates the severity of calcific aortic stenosis determined by two-dimensional (2-D) echocardiography with the aortic valve area determined by catheterization in 57 patients. Aortic valve leaflet calcification was diagnosed by cineangiography in 50 (88%) of 57 patients and by 2-D echo in 57 (100%) of 57 patients (p less than 0.025). An agreement between severity of aortic stenosis by catheterization and 2-D echo occurred in 22 (39%) of 57 patients. Chi-square and logistic regression analyses showed no correlation between the severity of aortic stenosis and the 2-D echo variables: left ventricular wall thickness, left ventricular diastolic dimension, left ventricular systolic dimension, aortic root diameter, and left atrial dimension. We conclude that 2-D echo detects aortic leaflet calcification better than cineangiography. However, the severity of aortic stenosis determined by 2-D echo correlates poorly with the severity of aortic stenosis determined by cardiac catheterization.

Cardiac conduction defects in patients older than 60 years with aortic stenosis with and without mitral anular calcium

The prevalence of conduction defects was investigated in 51 patients older than 60 years with aortic stenosis (AS) who underwent aortic valve replacement. Thirty one of the 51 patients, (61%) had associated mitral anular calcium (MAC). The mean age and prevalence of coronary artery disease, systemic hypertension and diabetes mellitus were similar in both groups. The prevalence of conduction defects (atrioventricular block, sinoatrial disease, bundle branch block, left anterior hemiblock or intraventricular conduction defect) was 18 of 31 (58%) in patients with MAC and 5 of 20 (25%) in patients without MAC (p less than 0.025). We conclude that patients older than 60 years with AS have a high prevalence of MAC, and that the prevalence of conduction defects is higher in patients older than 60 years with combined AS and MAC than in patients with AS without MAC.

Conduction disturbances related to the site and severity of mitral anular calcification: a 2-dimensional echocardiographic and electrocardiographic correlative study

To investigate an apparent association of mitral anular calcium (MAC) and electrocardiographic abnormalities, the relation between location of 2-dimensional (2-D) echo-quantified MAC and conduction disturbances was studied in 140 patients with MAC (MAC group) and in 135 age- and sex-matched patients without MAC (control group). The MAC group was subclassified regarding site and severity of calcium in the mitral anulus. The site of MAC was defined as Type I, near the primary conduction system--MAC located in the medial segment and/or extending to the anterior mitral leaflet; and Type II--MAC located at the central and/or lateral segments away from the primary conduction system. The severity of MAC was graded on 2-D echocardiography as mild (localized within 1 segment) and moderate to severe (greater than 1 segment). Seven patients with MAC, and only 1 control subject, had pacemakers in place. Conduction disturbances were present in 44 (31%) of 140 patients with MAC, and in 37 (27%) of 135 control patients (difference not significant). But there were more conduction disturbances in patients with Type I MAC (53%) than in those with Type II MAC (26%) (p less than 0.01). Specifically, complete left bundle branch block and intraventricular conduction delay were more prevalent when MAC was near the conduction system. Conduction disturbances also were more prevalent in patients with Type I MAC than in the control group: intraventricular conduction delay (Type I, 12% versus control, 4%; p less than 0.05) and total conduction disturbances (53 versus 28%; p less than 0.01). These data suggest that moderate to severe degrees of MAC located near the conduction system are associated with conduction disturbances, especially intraventricular conduction delay.

Clinical and echocardiographic characteristics of patients with mitral anular calcification. Comparison with age- and sex-matched control subjects

The clinical and echocardiographic features of 104 patients (53 women and 51 men) with mitral anular calcification (MAC) were compared with those of 121 age- and sex-matched control subjects (62 women and 59 men) without MAC. The incidence of coronary artery disease, rheumatic heart disease, systemic hypertension, and diabetes mellitus was similar in both groups. Patients with MAC had a greater incidence of cardiomegaly (p less than 0.001), cardiac conduction defects (p less than 0.001), and aortic outflow tract murmurs (p less than 0.005) than did control patients. Patients with MAC and without aortic root calcification had a higher incidence (p less than 0.001) of conduction defects than did patients with aortic root calcification without MAC. Control patients with and without aortic root calcification had a similar incidence of conduction defects. A higher incidence of atrioventricular block (p less than 0.025) and bundle branch block or left anterior hemiblock or intraventricular conduction defect (p less than 0.05) was present in anterior MAC than in posterior MAC. In conclusion, patients with MAC have a higher incidence of cardiomegaly, cardiac conduction defects, and aortic outflow tract murmurs than a control group.