A rare cause of idiopathic right outflow tract premature ventricular contraction: Type-4 renal tubular acidosis.

The premature ventricular contractions (PVCs) have usually good prognosis in patients without structural heart disease. In case of left ventricular ejection fraction depression or symptoms, antiarrhythmic drugs or cardiac ablations could be an option for management. We present a case of a patient with high burden of PVC admitted for cardiac ablation. Preoperative assessment revealed hyperkalemia and metabolic acidosis which ended up with type-4 renal tubular acidosis (RTA). Its rare cause and management may draw attention to the possibility of type -4 RTA as the cause of the PVC, and hyperkalemia.

An Exceptional Neurosurgical Presentation of a Patient with Osteopetrosis.

BACKGROUND: Osteopetrosis (OP) is a varied clinical condition caused by malfunction or insufficient development of osteoclasts, or both. Neurologic findings can occur because of osteopetrotic conditions restricting neural foramina through which the spinal cord, cranial nerves, or major vascular structures traverse the skull. Renal tubular acidosis (RTA) is a well-documented condition with OP. However, Chiari I malformation is rarely reported concomitantly with OP. CASE DESCRIPTION: We present a patient with a known RTA who was admitted with a rapid progressive tetraparesis within 24 hours. Clinical and radiologic evaluation of the patient revealed OP with RTA together with Chiari I malformation and holocord hydromyelia. Management of the patient was started with correction of severe hypokalemia (K: 1.4 mEq/L), which resulted in dramatic improvement in tetraparesis. Two days later, a posterior fossa bone decompression with ventriculoperitoneal shunt placement during the same session led to prominent decrease in size of the ventricles and the hydromyelia on long-term follow-up. CONCLUSIONS: Patients with OP can exhibit many clinical conditions. However, our case involved an unusual and rapid progressive tetraparesis, which could confuse the management as necessitating an emergent posterior fossa decompression. Stabilizing the metabolic status of the patient facilitated elective surgery, which further improved patient's neurologic findings and diminished hydromyelia on long-term follow-up.

Renal histopathology of stone-forming patients with distal renal tubular acidosis.

To define the renal tissue changes in stone-forming patients with distal renal tubular acidosis (dRTA), we performed intra-operative papillary and cortical biopsies in five patients. The main abnormalities were plugging of inner medullary collecting ducts (IMCD) and Bellini ducts (BD) with deposits of calcium phosphate in the form of apatite; epithelial cell injury and loss was marked. Plugged ducts were surrounded by interstitial fibrosis, but the fibrosis was generalized, as well, and was a main feature of the histopathology even when plugging was not present. In contrast, common idiopathic calcium oxalate stone formers (SF) never manifest intra-tubule crystals or interstitial fibrosis. Patients with brushite (calcium monohydrogen phosphate) stones and those with cystine stones have many fewer IMCD and BD plugged with apatite (or cystine, in cystinuria), and interstitial fibrosis is limited to the regions around plugged ducts. Patients with dRTA often present a radiographic picture of nephrocalcinosis. Our direct surgical observations reveal that these may be surgically removable stones, especially in patients with well preserved renal function. In all, dRTA SF have a more diffuse papillary renal disease than other SF thus studied, and are also unusual for the degree of interstitial fibrosis.

[Primary hyperaldosteronism without arterial hypertension]. / Primärer Hyperaldosteronismus ohne arterielle Hypertonie.

Treatment-resistant hypokalaemia (2.27 mmol/l) developed in a 43-year-old woman. Plasma renin activity was depressed (0.24 ng/ml.h), aldosterone and hydroxycorticosterone concentrations were elevated (123 ng/dl and 688 ng/dl, respectively). Mean blood pressure value (30 readings) was 133/88 mm Hg. An adrenal adenoma was diagnosed by ultrasound, computed tomography and subtraction angiography and then removed. Postoperatively the signs of hyperaldosteronism (Conn's syndrome) regressed and the average blood pressure was 112/76 mm Hg. Blood-gas analysis, which preoperatively had shown a minimal metabolic alkalosis, now revealed a mild metabolic acidosis. Preoperatively present bilateral renal calcifications in the region of the papillary tips were confirmed by computed tomography. An acid loading test revealed diminished renal acid secretion, making the diagnosis of distal renal-tubular acidosis. The latter, in combination with the primary hyperaldosteronism, may have been the cause of the low blood pressure, unusual in Conn's syndrome.